Biological Approach

1. What is the Biological Approach?

Definition: Biological psychology = how the physical systems of the body — brain, nervous system, hormones — influence the way we act, think and feel; and how we are shaped by our genes and evolution.

• Everything you do is controlled by biology: running (brain → messages along neurons in arms & legs), exam decisions (brain), crying (brain + hormones).

• Even "doing nothing" ⇒ brain still active = electrical + chemical signals along and between neurons.

• Adrenalin example: released when you run away scared ⇒ extra blood to muscles ⇒ run faster ⇒ survive. Evolved response ⇒ must be genetically controlled (to be affected by evolution).

• Dreaming example: if you acted out a dream (jumping out of a window) = very risky ⇒ a protective system evolved: during dreaming almost all muscles are paralysed (except the ones round the eyes).

The 3 core studies at a glance

Study	Method / data	Psychology investigated
Dement & Kleitman (1957)	experimental + correlational; EEG + interviews	sleep, dreaming, ultradian rhythms
Hassett et al. (2008)	(field) experiment; observing & coding monkeys' reactions to 'boy' & 'girl' toys; compared with children data from a different study	sex differences, socialisation, play, role of hormones
Hölzel et al. (2011)	brain scans (MRI) + questionnaires; longitudinal	how mindfulness training changes brain structure; localisation of function

2. Main Assumptions

Assumption in the studies	Where you see it
Brain / nervous system	D&K: EEG brain waves & eye-muscle activity (EOG) link to dreaming · Hölzel: MRI grey matter in hippocampus, PCC, TPJ, cerebellum
Hormones	Hassett: testosterone / oestrogen → sex differences in toy preference
Genes & evolution	REM paralysis protects us (evolved); capacity to dream exists even in a foetus; monkeys as a model for human behaviour
Interaction with environment	Hölzel: experience (MBSR course) changed brain structure · Hassett: biology + gender stereotyping/socialisation

3. Brain, Neurons & Hormones

Cognitive psychology compares the mind to a computer. In biological terms the brain (the structural element of the 'mind') is not like a computer — it is a living organ made of cells.

• Cells of the brain = neurons; with the nervous system they are specialised for communication.

• Neurons send electrical signals along their length & interact using chemicals at synapses (branch-like projections of different neurons come very close).

• In the brain, neurons form areas with specific jobs (e.g. vision, hearing).

Hormones

Hormones = chemicals released from glands into the bloodstream; they travel round the body in the blood to communicate between organs.

Gland	Hormone	Notes
adrenal glands	adrenalin	released in response to fear
testes	testosterone	mainly 'male' hormone; an example of an androgen
ovaries	oestrogen	mainly 'female' hormone

	Nervous system	Hormones
speed	very rapid	slower
how long	short-lived messages	longer lasting
route	neurons	bloodstream → target organs

4. Genes, Evolution & Individual Differences

Gene: a hereditary unit — an instruction passed from parent to child, coded in DNA (deoxyribonucleic acid); controls development & influences e.g. personality and intelligence.

• Everyone's genes are individual — except identical twins.

• Genes determine biological structure & function (incl. brain & nervous system) ⇒ underpin many functions.

• But biological systems are also affected by the environment ⇒ psychologists study how genes + environment interact to produce behaviour, cognitions, emotions.

Evolution & natural selection

Evolution: the consequence of natural selection — offspring that inherit beneficial characteristics are more likely to survive.

When genes pass between generations, changes called mutations can occur ⇒ variation between individuals ⇒ may be an advantage when the environment is challenging.

Individual differences

Identical twins have the same genes but are not entirely the same (different interests, likes, dislikes, abilities) because our psychological makeup = genes + environment.

• Environment = physical situation + the people around us + opportunities + experiences (family, school life, resources like books, events like holidays, even injuries).

• Cultural, social & personal experiences work with our biology to create individual differences = all the ways people vary (e.g. intelligence, emotions, personality).

5. Core Study 1 — Dement & Kleitman (1957): Sleep & Dreams

Ref: Dement, W. & Kleitman, N. (1957). The relation of eye movements during sleep to dream activity: an objective method for the study of dreaming. Journal of Experimental Psychology, 53, 339–346.

① Psychology being investigated

• Sleep = altered state of consciousness: less aware of surroundings, move very little (reduced conscious awareness & movement, daily cycle). Happens despite the risk (vulnerability) in our evolutionary history.

• Circadian rhythm = cycle repeating ~every 24 h (e.g. sleep/wake).

• Ultradian rhythm = cycle repeating more often than daily. The basic rest–activity cycle (BRAC) ≈ every 90 min through day & night; in sleep it controls the stages of sleep (e.g. periods of dreaming every 90 min).

Problem: a sleeper is unresponsive ⇒ can't report their experience. Solution: the electroencephalograph (EEG) — detects & records electrical activity of nerve & muscle cells when many are active together, using macro-electrodes (large electrodes stuck to the skin/scalp). They only record — they can't give a shock!

• EEG chart ("brain waves") changes in frequency (how rapidly waves occur; cycles per second = Hz, e.g. beta 13–30 Hz) and amplitude ('height' = voltage).

• These change in a patterned way over time ⇒ show which sleep stage you are in.

Typical night: Stage 1 → 2 → 3 → 4 (deeper, harder to wake) → back up 3 → 2 → but instead of stage 1 we go into 'dream sleep' (REM) → repeat several times.

• As the night goes on: time in dream sleep ↑ and depth of each cycle ↓.

• Total length of each cycle stays ≈ the same ⇒ the ultradian rhythm is kept.

Dreams & eye movements

Dreams = vivid, generally visual sequences of imagery during sleep (regular intervals; linked to rapid eye movements). No machine can 'read' dreams ⇒ the sleeper must be woken to describe it.

• BUT the EEG can detect activity in the muscles that move the eyes ⇒ measures frequency & direction of eye movements. The recording = electrooculogram (EOG).
• In dream sleep eye movements are faster than in any other stage ⇒ rapid eye movement (REM) sleep (≈ 60 eye movements per min). The other stages (1–4) = non-REM (nREM) sleep: eyes still, 'quiescent' (quiet), not associated with dreaming.

② Background — Aserinsky & Kleitman (1955)

• Began the objective, physiological measurement of sleep using EEG to study sleep & dreaming.

• Participants woken from REM were more likely to report a vivid visual dream than when woken in other stages.

• Found a characteristic brain-wave pattern in REM (the book calls them alpha waves) similar to the awake brain — but all other body muscles are completely inactive in REM.

• From the EOG they got frequency of eye movements; with electrodes in different places they could tell horizontal vs vertical movements.

• Checked accuracy: compared the EOG with deliberate movements in waking participants, and with watching & filming the sleeping eyes.

• Showed REMs happen simultaneously in both eyes & on a 90-min cycle.

• Also found ↑ breathing & heart rate in REM ⇒ REM = a particular level of body activity.

• Kleitman suggested REMs are linked to the experience of dreaming; strikingly vivid visual reports ⇒ eye movements may match the visual imagery — but this is hard to test ⇒ D&K aimed to explore this exact problem.

③ Aim — 3 questions

1. Does dream recall differ between REM and nREM ('quiescent') sleep?
2. Is there a positive correlation between subjective estimates of dream duration and the length of the REM period before waking?
3. Are eye-movement patterns related to dream content?

④ Method

Method & design: conducted in a laboratory but several methods were used:

Question	Method	Variables
Q1 REM vs nREM recall	Experiment – repeated measures design	IV = woken from REM or nREM · DV = recalled a dream or not
Q2 duration	Correlation (REM length vs words) + 2nd repeated-measures experiment (estimate 5 or 15 min)	REM duration (min) ↔ words in dream narrative · estimate vs actual
Q3 eye movements	Self-reports compared with direction of eye movements observed	eye-movement pattern ↔ dream content

Sample: 7 male + 2 female adults (9 total). 5 studied in detail; results from the remaining 4 used to confirm the first five.

⑤ Procedure

• Each study day the participant ate normally but no caffeine (coffee) or alcohol; arrived at the lab just before normal bedtime.

• Slept in a dark, quiet room; electrodes beside the eyes & on the scalp (EEG) fed into the experimenter's room; wires gathered into one cord from the head (like a pony-tail) so they could move easily.

• Woken by a doorbell at various times, asked to describe their dream if they had one, then back to sleep. Not told about their EEG pattern or whether their eyes were moving.

⑥ Results

General: all participants dreamed every night. Uninterrupted dream stages:

• lasted 3–50 min (mean ≈ 20 min) · typically longer later in the night

• showed bursts of ≈ 2–100 rapid eye movements

• No REMs at sleep onset even though EEG passed through REM-like waves

• Cycle length (REM to next REM) varied 70–104 min between participants (mean 92 min) but was consistent within individuals

• Woken from nREM → returned to nREM; woken from REM → typically no dream until next REM phase (except sometimes in the final REM phase) ⇒ pattern of REM/nREM in disturbed sleepers ≈ undisturbed sleepers.

Participant	Rapid eye movements (REM)		No rapid eye movements (nREM)
	Dream recall	No recall	Dream recall	No recall
DN	17	9	3	21
IR	26	8	2	29
KC	36	4	3	31
WD	37	5	1	34
PM	24	6	2	23
KK	4	1	0	5
SM	2	2	0	2
DM	2	1	0	1
MG	4	3	0	3
Totals	152	39	11	149

• nREM recall was most noticeable at the end of the nREM period: in 17 nREM awakenings soon after the end of a REM stage (within 8 min) 5 dreams recalled (29%); of 132 awakenings > 8 min after REM only 6 recalled (< 5%).

• In nREM people described feelings, not specific dream content — bewildered; anxiety, pleasantness, detachment. Least likely to remember in stage 2 (spindles).

• REM with no recall (39) was more common early in the night: 19 in the first 2 h, 11 in the 2nd 2 h, 5 in the 3rd, 4 in the last 2 h.

• DN was no more/less likely to report in REM or nREM than the others even though he could have learned the 3-REM/3-nREM pattern. Participants did not get more accurate over time (no improvement with practice).

Participant	5 minutes		15 minutes
	correct	incorrect	correct	incorrect
DN	8	2	5	5
IR	11	1	7	3
KC	7	0	12	1
WD	13	1	15	1
MP	6	2	8	3
Total	45	6	47	13

Awake (control) participants: eye movements similar in amplitude & pattern to those in dreams. Virtually none when watching distant activity, much more for close-up. Vertical movements were rare when awake (except blinking, and when the experimenter threw a ball in the air).

⑦ Conclusion

• Dreaming is experienced in REM but not nREM sleep.

• Participants can judge the length of a dream; REM patterns relate to dream content.

• Dreaming is more likely late in the night (REM stages are longer) — fits other researchers.

• Occasional nREM recall = dreams remembered from the previous REM phase (more likely just after REM).

• REM happens in phases ⇒ explains why other studies that woke people at random may have missed dreams: woke in nREM, or dreamed about distant objects (few REMs, hard to detect).

• EEG measures of eye movement + brain waves = objective evidence that dreams progress in 'real time' ⇒ a more valid way to study dreaming than recall alone (subjective, affected by forgetting).

⑧ Strengths & weaknesses

✓ Strengths	✗ Weaknesses
Laboratory experiment ⇒ limited uncontrolled variables (e.g. loud doorbell woke them instantly from any stage so nobody forgot more).	Correlation (REM time ↔ words) shows only a link, not a causal relationship.
Not told EEG pattern / eye movements (or given false info) ⇒ fewer demand characteristics.	Small sample (9 in total) limits generalisability; volunteers for a dream study may dream more, remember better, or have more visual dreams.
Changing the estimate task to 5 vs 15 min (more controlled) ↑ validity (fewer participant variables like recall ability).	Narrative length also depends on how expressive the participant is ⇒ more subjective.

✓ Strengths	✗ Weaknesses
'Dream' operationalised (content, not just an impression) ⇒ valid.	Low ecological validity: no coffee/alcohol (unusual for some), sleeping in a lab, wired to machines, observed.
EEG = objective biological measure; unaffected by experimenter's view; consistent electrode placing ⇒ reliable; similar to earlier studies. Quantitative and qualitative data.	Unusual situation overall for sleeping.
Both genders in sample (men & women may dream/report differently).

⑨ Summary

D&K studied the relationship between eye movements during sleep and dream recall. EEG gave sleep stages; recall = self-report. Correlation: estimates based on number of words ↔ REM duration (positive). Lab experiments: dreams occur in REM not nREM; participants can tell if they'd dreamed for 5 or 15 min; dream content ↔ EOG direction & amount (vertical movements when vertical events). Many variables (food, drink) controlled and demand characteristics reduced; but lab/equipment unusual for sleep. Objective, quantitative EEG/eye/timing data ⇒ valid & reliable comparisons.

6. Core Study 2 — Hassett et al. (2008): Monkey Toy Preferences

Ref: Hassett, J. M., Siebert, E. R. & Wallen, K. (2008). Sex differences in rhesus monkey toy preferences parallel those of children. Hormones and Behavior, 54(3), 359–364.

① Psychology being investigated

Sex differences = ways males & females differ that are caused directly by sex — physical and behavioural. There are differences in male/female brains and hormones.

• Brain: language is localised in the left hemisphere in both sexes, but in women language functions are relatively bilateral (spread over both sides).

• Hormones: after puberty males have ≈ 10× more testosterone than females; females have much more oestrogen.

• Hard to tell how much of a behavioural difference is biological (due to sex) vs social (different treatment of boys & girls).

• Socialisation: boys watch, copy & are rewarded for behaving like men (tough, active, oriented to doing things); girls are rewarded for copying women ⇒ more passive & caring. So socialisation is partly determined by gender.

• Play differences: boys — active, sometimes aggressive; guns, toy tractors, building sets. Girls — nurturing; dolls, playhouses, kitchen sets. Toys = 'masculine' or 'feminine' by gender stereotype.

• This socialisation influence has long been assumed to be the primary cause of gender differences in play.

② Background

• Humans are complicated (brain + social & physical environment) ⇒ hard to study. A lab experiment can control other variables & use a control condition — but isolating variables in children's development is impossible ethically/practically.

• Earlier finding: prenatal hormone exposure affects toy preference. Girls with a genetic condition giving ↑ androgens in the womb preferred 'boys' toys' more than unaffected sisters/control females — even with extra socialisation towards 'female-appropriate' activities. Such cases are rare and uncontrolled variables remain (exact hormone amount; amount of gender socialisation).

• Unethical to deliberately expose foetuses/children to hormones or remove environmental factors.

• Model = a simpler, smaller-scale representation of a phenomenon. Higher primates are genetically close to humans, with very similar behaviours ⇒ a model for human development where experience can be controlled.

• Rough-and-tumble play, peer preferences & interest in infants differ by gender in children and primates (males: more rough-and-tumble, less interest in infants).

• Young primates, like young humans, differ in hormones: prepubescent males ↑ testosterone (strength, aggression, and in humans spatial skills); young females ↑ oestrogen (in adult females linked to nurturing, e.g. caring for offspring).

③ Aim

④ Method

• Field experiment: tested in their normal outdoor housing area. Toys were new, but objects being placed in enclosures wasn't unfamiliar.

• IV = sex/gender of monkey (male or female) — independent measures. DV = activities with the toys, measured by observation.

• Correlation: individual monkeys' social rank vs frequency/duration of activities with each toy type.

• Finally monkey data compared with children's data from a different study (independent-measures comparison).

Sample: 21 male + 61 female rhesus monkeys living in natal (birth) groups, part of a group of 135 at the Yerkes primate research station, USA. Excluded: 14 adults (had received hormone treatments) & 39 young infants (couldn't be reliably identified). (135 − 14 − 39 = 82.)

Each group: 25 × 25 m outdoor area + temperature-controlled indoor area; water available, standard monkey feed twice daily + fruit & vegetables once daily.

⑤ Procedure

• Toys divided into 2 categories by properties as objects (not by gender-typing — though the result matched the traditional 'boys'/'girls' split): wheeled toys (typically boys) & plush toys (soft, cuddly; typically girls). They differed in size, shape & colour too.

• 6 wheeled (16–46 cm): wagon, truck, car, construction vehicle, shopping cart, dump truck. 7 plush (14–73 cm): Winnie-the-Pooh, Raggedy Ann, koala hand puppet, armadillo, teddy bear, Scooby-Doo, turtle.

• Per social group: 7 trials, each 25 min, filmed with 2 video cameras. Trial start: all monkeys indoors while 1 plush + 1 wheeled toy placed 10 m apart outdoors. One camera on each toy. Toy positions counterbalanced left/right across trials.

• After each trial toys removed; video analysed by two observers working together to reach a consensus. They identified each animal interacting with a toy & coded the activity with a behavioural checklist (below); recorded exact time, frequency and duration of continuous activities.

Behaviour	Operational definition	Behaviour	Operational definition
Extended touch	hand/foot placed on toy	Turn entire toy	shifting 3-D orientation
Hold	stationary support with 1+ limbs	Touch	brief contact, hands/fingers
Sit on	seated on toy / part of it	Sniff	nose very close to toy
Carry in hand	moving with toy in hand, off ground	Mouth	brief oral contact — no biting/pulling
Carry in arm	moving with toy in arm, off ground	Destroy	mouth/hands to bite or tear toy
Carry in mouth	moving with toy in mouth, off ground	Jump away	approach, then back away with a jumping motion
Drag	moving toy along ground behind animal	Throw	project into air with hands
Manipulate part	moving, twisting or turning a part

⑥ Results

Data prep: records for each behaviour converted into an overall average frequency & duration per individual (animals took part in different numbers of trials). Those with fewer than 5 recorded behaviours were dropped (book: 14 males & 3 females). Final analysis: 11 males + 23 females.

Toy type	Sex	Frequency		Duration (min)
		Mean	SD	Mean	SD
Wheeled ('masculine')	Male	9.77	8.86	4.76	7.59
	Female	6.96	4.92	1.27	2.2
Plush ('feminine')	Male	2.06	9.21	0.53	1.41
	Female	7.97	10.48	1.49	3.81

Comparison	Frequency data	Duration data
Within males	preferred wheeled > plush	longer with wheeled than plush
Within females	no preference for plush over wheeled	similar time with wheeled & plush
Between sexes	females interacted with plush more than males; no sex difference for wheeled	no significant difference ⇒ no overall difference in time

• 'Magnitude of preference' — males: total frequency wheeled − total frequency plush; females: plush − wheeled (same for duration) ⇒ males have a higher preference for 'masculine' toys than females have for 'feminine' toys.

	Males (%)	Females (%)
Preference for wheeled toys	73	39
Preference for plush	9	30
No significant preference	18	30

• Social rank: sex differences still evident when ranks were taken into account. Combined M+F: rank positively correlated with total frequency for wheeled and plush. Males: neither frequency nor duration correlated with rank. Females: rank + with frequency (both toys); with duration only for plush. ⇒ rank may matter in females but unlikely to explain the sex differences overall.

• Age: sample too small for detailed analysis, but juvenile / subadult / adult / old adult did not differ in frequency or duration for either toy type.

• Children comparison: monkeys' frequency vs children's duration (Berenbaum & Hines, 1992): very similar patterns. Both: males → masculine toys, females → feminine; and the preference is much more marked for males than females.

⑦ Conclusion

• Like boys, male monkeys have a strong preference for masculine-type (wheeled) toys; female monkeys, like young girls, are more variable. Male preference for masculine > female preference for feminine.

• Findings support a biological explanation: preferences develop in the absence of socialisation (in monkeys only hormonal differences, not social, can cause differences in development).

• Importance: biologically-driven differences could interact with social pressures on children — boys choosing 'girls' toys' get more negative responses than girls choosing 'boys' toys' ⇒ reinforces a pre-existing tendency for boys to be more masculine, girls more variable.

⑧ Strengths & weaknesses

✓ Strengths	✗ Weaknesses
Using animals eliminates the effect of socialisation.	Monkey–child comparison differed: toys for monkeys chosen by object properties, not as gender-stereotyped children's toys.
Excluded confounding variables: age (known — group established 25+ years) & social rank (from observing grooming, dominance, submissive behaviour). Analysis: little effect on the sex differences.	'Masculine'/'feminine' play measures differed; children from a different study with different toys, measuring duration only. The key comparison = monkeys' frequency vs children's duration.
Standardised, clear operational definitions ⇒ ↑ reliability; standard 25-min trials (one stopped 7 min early — plush toy torn to pieces).	Children tested individually, monkeys in groups — methodological difference (testing monkeys in groups could have influenced findings).

⑨ Summary

Hassett et al. asked whether rhesus monkeys show child-like sex differences in toy preference. Children's data can't separate biology from social effects; in monkeys the role of hormones without socialisation is clear. Videoed groups with a masculine (wheeled) + feminine (plush) toy were coded with a behavioural checklist: males, like boys, prefer masculine toys; females, like girls, have less fixed preferences ⇒ evidence for a biological explanation since monkeys' preferences developed without socialisation.

7. Core Study 3 — Hölzel et al. (2011): Mindfulness & Brain Scans

Ref: Hölzel, B., Carmody, J., Vangel, M., Congleton, C., Yerramsetti, S., Gard, T. & Lazar, S. (2011). Mindfulness practice leads to increases in regional brain gray matter density. Psychiatry Research, 191(1), 36–43.

① Psychology being investigated — localisation of function

Localisation of function = particular brain areas are responsible for different activities. (Early psychologists thought the shape of the skull had meaning; now we focus on brain regions.)

• Motor cortex – deliberate movements · somatosensory cortex – skin & muscle sensation · Broca's & Wernicke's areas – language · brain stem (pons) – control of sleep & dreams · cerebellum – 'automatic'/well-learned movements.

• Brain is roughly symmetrical ⇒ many areas are bilateral (in both left & right hemispheres). Motor & somatosensory cortex are on both sides (left side of brain ↔ right side of body, and vice versa). Broca's & Wernicke's are usually only in the left hemisphere.

• Localisation can be investigated by studying dead bodies or using surgery (animals & humans) — and now by brain scans.

Scan type	Shows
Structural (e.g. MRI)	detailed pictures of the shape of brain areas
Functional	activity levels in different brain areas

• Participant lies on a bed that enters a narrow tube; loud noise inside; some find it confining (open at the feet). Painless & harmless — but unsuitable for people with metals (pacemakers, plates, shrapnel): attracted to the magnet.

The hippocampus (a region investigated here): involved in memory & navigation, believed to help control emotion and the arousal/responsiveness of the cortex ⇒ could be involved in effects of mindfulness meditation. It shows plasticity = capable of creating new neurons & many new synapses. e.g. stress ↓ hippocampal volume; antidepressants ↑ it.

Mindfulness = a state, reached through meditation, that increases awareness of present-moment experience and lets you look at yourself in a compassionate, non-judgemental way. You become more aware of current experience, physical sensations, thoughts & feelings ⇒ enjoy life more (appreciate smells, sounds, sights), notice signs of anxiety/stress/depression and act earlier. Mindfulness meditation = formalised way: silence + attention to oneself (thoughts, sensations, sounds such as the rhythm of breathing).

② Background

• Mindfulness = thinking + sensations processed by the brain ⇒ could study which part(s) of the brain are involved. Early studies used EEG (as in D&K); now MRI gives precise measurements: size of structures; amount of grey matter (cell bodies of neurons) vs white matter (axons).

• MRI detects small structural changes in grey matter over time — seen after training in physical skills & cognitive skills: juggling, medical students revising for exams, mirror reading.

• Earlier studies were cross-sectional (compared different groups: those who meditate vs those who don't) ⇒ differences found may be pre-existing (e.g. people who choose to meditate may already have more grey matter) ⇒ misleading conclusion that meditation increased grey matter.

③ Aim

④ Method

Method & design: an experiment using a longitudinal design — one group tested pre & post an intervention, and also compared with a control group.

• IV = exposure to an 8-week Mindfulness-Based Stress Reduction (MBSR) course: a 2½-hour session each week for 8 weeks + a full-day session in week 6. Trained in present-moment awareness & a compassionate non-judgemental view.

• Exercises: body scan (attention guided through whole body, ends with perception of body 'as a complete whole') · mindful yoga (gentle stretching, slow movements, breathing) · sitting meditation (sensation of breathing → sounds, sights, tastes, body sensations, thoughts & emotion).

• 45-min guided recording given to each participant to practise daily at home ('homework'). Sessions also covered mindfulness in daily life (eating, walking, washing dishes, showering) and using it to cope with stress.

• MBSR vs control MRI comparison = independent measures design.

• DV = change in grey matter (MRI). Also questionnaires measuring 5 mindfulness scales before & after.

	MBSR (experimental)	Control (wait-list)
Initial sample	8 males + 10 females → 16 (2 males left after 1st MRI — discomfort)	7 males + 10 females
Mean age	38 years (SD 4.1)	39 years (SD 9.2)
Ethnicity	13 Caucasian, 1 Asian, 1 African American, 1 multi-ethnic	13 Caucasian, 2 Asian, 2 African American, 1 Hispanic

• Sample: recruited from people already enrolled on MBSR courses at the University of Massachusetts — enrolled for stress reduction (own choice or doctor-referred). All: physically & psychologically healthy, not on medication; limited meditation experience (none in last 6 months; max 4 in last 5 years or 10 in lifetime); aged 25–55; safe for MRI (no metal, not claustrophobic); committed to attend all sessions & do homework.

• Control group: same eligibility criteria as experimental group — a 'wait-list' control (waiting for admission to the course). The two groups did not differ in education level.

• Ethics: approved by the University of Massachusetts Institutional Review Board; all gave written consent; received a discounted MBSR course fee.

⑤ Procedure

Both groups completed the Five Facet Mindfulness Questionnaire (FFMQ) — 39 items measuring 5 facets:

Observing	noticing internal & external stimuli (thoughts, feelings, sensations, sights, sounds, smells)
Describing	mentally labelling observations with words
Acting with awareness	attentive to current actions vs automatic / absent-minded
Non-judging	(of inner experience) not evaluating sensations, thoughts or emotions
Non-reactivity	(to inner experience) letting thoughts & feelings drift in & out

• Each item = a statement answered on a 5-point Likert-type scale: never/very rarely true (1) … very often/always true (5).

• Reverse-scored items too: for these a mindful person answers 'rarely/never true' and gets 4–5.

• Subscale total = add its items (7 or 8 items each); added together = total FFMQ score. Experimental group did it before & after; controls did it twice. 14 per group gave useable data at both times.

Item idea (Baer et al. 2006 extract)	Type	Mindful answer	Score
1 · deliberately notice body sensations when walking	normal	very often true	5
3 · criticise self for irrational/inappropriate emotions	reversed	never/rarely true	5
4 · perceive feelings without having to react	normal	very often true	5
5 · mind wanders, easily distracted	reversed	never/rarely true	5

• MRI scans: both groups scanned twice. Experimental: 2 weeks before & 2 weeks after the 8-week MBSR (gap ≈ 56 days) = pre/post tests. Controls: gap ≈ 66 days.

• MRI data used 2 ways: regions of interest (RoI) analysis — bilateral hippocampi & bilateral insulae — and whole-brain analysis (other regions possibly affected).

• Participants also reported time spent on formal homework over the 8 weeks & time on each exercise (body scan, yoga, sitting meditation).

⑥ Results

Homework: MBSR participants averaged 22.6 hours over the course ≈ 27 min/day. None of the 3 measures significantly correlated (body scan vs sitting r = −0.26; yoga vs sitting r = 0.49).

MBSR exercise	Min	Max	Mean	SD
Body scan	335	1002	699	217
Yoga	103	775	327	194
Sitting meditation	0	755	332	211

• FFMQ: useable data from 14 MBSR + 14 control. MBSR group significantly increased mindfulness on 3 subscales: acting with awareness, observing, non-judging. Compared with controls (not expected to change) the MBSR changes were significantly greater on all three.

• RoI – left hippocampus: no group difference at pre-test; no change in controls; significant ↑ in MBSR (group size 16). This did not correlate with homework time or changes in FFMQ. Grey matter in the other regions of interest did not change significantly.

• Whole-brain: 4 clusters ↑ significantly in MBSR: posterior cingulate cortex (PCC), left temporo-parietal junction (TPJ), and two parts of the cerebellum (lateral cerebellum; cerebellar vermis/brainstem) — significantly greater than controls. Again no correlations with homework or FFMQ change. No significant decreases in MBSR (small reductions in control).

	RoI	Whole-brain analysis
	Left hippo-campus	Posterior cingulate (PCC)	Left TPJ	Lateral cerebellum	Cerebellar vermis / brainstem
MBSR	+0.01	+0.01	+0.007	+0.015	+0.014
Control	+0.001	−0.005	−0.002	+0.001	−0.001

⑦ Conclusion

• RoI: structural changes in the left hippocampus arise within an 8-week course ⇒ hippocampal volume changes seen in other situations may also occur with mindfulness. Hippocampus → learning & memory ⇒ MBSR participants had learning experiences that changed grey matter.

• Whole-brain: ↑ in left TPJ, PCC, cerebellum in MBSR but not controls ⇒ participating in an 8-week mindfulness course causes structural changes (not specifically predicted, but fits other research).

Area	Role → link to mindfulness
TPJ	'self-referential processing' (unity of sense of self & physical body). If impaired → out-of-body experiences. Links to learning to perceive the body as a complete whole.
PCC	judging the relevance of stimuli to ourselves (emotional/autobiographical context) → noticing internal & external stimuli, moment-to-moment attention.
Cerebellum	regulating emotions & cognition for healthy psychological functioning.
Hippocampus + TPJ + PCC (+ parts of prefrontal cortex)	a network: recalling the past, thinking about the future, considering others' viewpoints (e.g. turn-taking) ⇒ autobiographical information lets us consider alternative perspectives = crucial step to a mindful state.

⑧ Strengths & weaknesses

✓ Strengths	✗ Weaknesses
Longitudinal (vs cross-sectional): avoids confounding participant variables; allowed time for the intervention to affect brain plasticity.	Interpretation of MRI results is much less objective: many unknowns about localisation and what volume changes mean — don't infer too much.
Control group ⇒ shows changes are not simply due to the passage of time.	No correlation between grey-matter increases and homework minutes or FFMQ change ⇒ practice minutes aren't the direct cause; effect likely from the MBSR programme as a whole.
MRI = quantitative data ⇒ statistical comparisons (pre/post; MBSR vs control).	To isolate mindfulness itself, need a control group given only the non-mindfulness parts: 7 weekly sessions + full day, social contact, belief it reduces stress, ongoing time committed to wellness.

✓ Strengths	✗ Weaknesses
Objective data: recorded volumes need no researcher interpretation.	MRI scanner experience (noisy, confining) is not ecologically valid — potentially emotional.
Participants can't alter grey matter in response to demand characteristics ⇒ ↑ validity.

⑨ Summary

An experiment with a longitudinal design: 8-week MBSR vs a wait-list control. All had 2 tests at start & end: MRI (grey-matter concentration) and FFMQ. Participants in the intervention kept a record of mindfulness activities. Grey matter ↑ in MBSR (vs controls) in left hippocampus, PCC, TPJ, cerebellum. MBSR mindfulness scores ↑ but did not correlate with brain changes. ⇒ MBSR can cause changes in grey matter in areas for learning, memory, self-referential processing, emotions and considering others' viewpoints.

8. Issues, Debates & Approaches

① Application of psychology to everyday life

Study	Application
D&K	EEG lets psychologists accurately detect dreaming ⇒ useful for assessing people with sleep & dream disorders (insomnia, nightmares, sleepwalking).
Hassett	Supports a biological explanation ⇒ socialisation is not the only important factor in gender-specific behaviour. Could mean some gender differences are inevitable ⇒ maintains disadvantage for people wanting careers typical of the opposite sex. OR (more beneficial) ⇒ stresses the need for gender-neutral socialisation so everyone can access all opportunities (gender-typed socialisation widens the male/female divide early).
Hölzel	MBSR significantly ↑ mindfulness. Mindfulness matters for self-referential processing ⇒ could help people with TPJ impairments (out-of-body experiences) by learning to perceive the body as a complete whole. Cerebellum areas changed are important for regulating emotion & cognition ⇒ another beneficial role.

② Individual & situational explanations

Hassett: shows a clear role for biology but recognises it interacts with situational effects of exposure to gender stereotyping in society — through cultural expectations, reinforcement & punishment of 'gender-appropriate/inappropriate' behaviour, and sheer exposure to stereotypes.

③ Nature versus nurture

The biological approach focuses mainly on the nature side ⇒ evidence from procedures like the EEG (physiological evidence of brain activity = direct evidence of underlying processes, e.g. link between dream content & eye movements).

Study	Nature	Nurture
D&K	Even a foetus experiences REM ⇒ capacity to dream = nature. Emotions' biological processes = brain & hormones.	Dream content relates to our experiences ⇒ explains differences between individuals.
Hölzel	Brain structure determined largely by nature ⇒ similarities between individuals and even humans & animals.	MBSR changed brain structure ⇒ even structures that seem highly constrained by biology can be influenced by experience.
Hassett	Biological effects likely due to sex hormones ⇒ enduring influence of nature.	Sex differences in children's play (often assumed socialisation) may not, after all, be entirely nurture.

④ The use of children & animals in psychological research

• Hassett used comparative psychology = finding evidence about human behaviour by comparison with animal models. Animals are less complex than humans & their environment/experience can be controlled ⇒ shows origins of human behaviours. Isolated biology (hormones) from experience (socialisation).

• Ethics: practical benefit but raises ethical issues. Arguably acceptable to manipulate rhesus monkeys' environments, whereas unacceptable to manipulate children's experiences so they miss culturally-driven socialisation.

• Animals & D&K / Hölzel? Non-human mammals show REM sleep (pets twitching/'running' in sleep) — studied extensively; dream content is hard to know. Done indirectly using brain-cell recording of repeated waking behaviours (bird song, rats running mazes): brain activity in sleep closely resembles waking behaviour ⇒ shows what animals are dreaming about.

9. Research Methods Toolkit

Term	Meaning · example from the chapter
Laboratory experiment	controlled setting; D&K (sleep lab) — can limit uncontrolled variables.
Field experiment	natural setting; Hassett (monkeys' own outdoor enclosure).
Repeated measures	same participants in both conditions — D&K (REM vs nREM; 5 vs 15 min).
Independent measures	different participants per condition — Hassett (male vs female); Hölzel (MBSR vs control).
Correlation	link between 2 variables, not causal — D&K REM minutes vs words; Hassett rank vs interactions. Coefficient r from −1 to +1.

Term	Meaning · example from the chapter
Longitudinal vs cross-sectional	same people over time (Hölzel) vs different groups at one time (earlier studies).
Observation / self-report / interview / questionnaire	Hassett (video + checklist) · D&K (dream reports, brief interview) · Hölzel (FFMQ, Likert scale).
Quantitative vs qualitative	numbers (EEG frequency/amplitude, grey matter %) ⇒ reliable · descriptions (dream narratives) ⇒ rich but subjective.
Reliability	consistency — EEG machine; operational definitions & inter-coder agreement (Hassett); similarity to earlier studies.
Validity / ecological validity	measures what it should / realistic — lab sleep & MRI tube are unnatural; operationalised 'dream'; reverse scoring ↑ validity.

Term	Meaning · example from the chapter
Demand characteristics	participant guesses the aim & changes behaviour — D&K kept them uninformed; can't alter grey matter on purpose.
Operational definition	exact measurable definition — 'dream' (with content), Hassett's behaviour checklist.
Counterbalancing	vary order/position — toy left/right in Hassett.
Practice effect	improvement through familiarity — possible for DN.
Confounding / participant variables	age & rank (Hassett), pre-existing brain differences (Hölzel cross-sectional), recall ability (D&K).

Term	Meaning · example from the chapter
Generalisability / sample	D&K: 9 people; Hassett: 11 M + 23 F rhesus monkeys; Hölzel: 16 + 17, mostly Caucasian, stressed volunteers 25–55.
Objective vs subjective	EEG, MRI volumes = objective · dream reports/narrative length = subjective.
Ethical guidelines	informed consent, deception, right to withdraw, protection from harm, animal welfare (see ethics boxes).

10. The 3 Studies Compared

	Dement & Kleitman	Hassett et al.	Hölzel et al.
Year	1957	2008	2011
Aim	3 Qs: recall REM vs nREM? estimate ↔ REM length? eye movement ↔ content?	do monkeys' toy preferences resemble children's ⇒ biological?	grey-matter changes before/after mindfulness course (longitudinal)
Method	lab experiment (repeated measures) + correlation + self-report	field experiment (independent measures) + observation + correlation	longitudinal experiment, pre/post + wait-list control; MRI + questionnaire
Sample	7 M + 2 F adults (5 in detail, 4 to confirm)	21 M + 61 F rhesus monkeys (final 11 M, 23 F); Yerkes, USA	16 MBSR + 17 control, aged 25–55, UMass
Key measure	EEG/EOG + dream reports	video-coded behaviours (frequency, duration)	MRI grey matter; FFMQ

	Dement & Kleitman	Hassett et al.	Hölzel et al.
Key result	152/191 REM recalls vs 11/160 nREM; 88%/78% accuracy; r 0.4–0.71; vertical ↔ vertical events	males: strong preference wheeled (73%); females mixed; pattern ≈ children	↑ grey matter in L hippocampus, PCC, TPJ, cerebellum in MBSR only; no correlation with homework/FFMQ
Conclusion	dreaming in REM; people judge dream length; eye movement relates to content	biological (hormonal) basis for toy preference	MBSR causes structural brain change
Main assumption	brain physiology / evolution	hormones & genes	brain structure + plasticity (nurture on biology)
Top strength	objective EEG; controlled lab	animals remove socialisation; confounds controlled	longitudinal + control group
Top weakness	tiny sample; low ecological validity	monkey–child comparison differences	interpreting MRI; no correlation with practice

	Dement & Kleitman	Hassett et al.	Hölzel et al.
Ethics	deception (WD)	animal welfare; toy destroyed	wait-list; withdrawal; MRI safety

11. Exam-style Questions — How to Answer

12. Activities, Project & Self-check

• Activity 2.3: if you had a brain scanner, which function would you locate & why? (explain to a partner / write to a psychologist). Peer assessment: present it; judge how convincing. Discuss: advantage of specialised locations vs tasks distributed across the brain (try opposing views).

• Activity 2.4: look up the FFMQ online (free pdfs, short versions) — read the questions & scoring.

• Project — dream diary: for a week on waking: guess how long the dream lasted → write it down → cover/turn page → write what you remember → think whether the dream had many/few eye movements & vertical/horizontal. Then: count words in each narrative, convert time to whole units, table (row per day: time estimate, word count), draw a scatter graph ⇒ positive correlation? If not, how to improve? Also compare dream recall at night-waking vs morning waking. Final piece: a shareable dream narrative · raw data table · scatter graph · answers.