B&C Psychology Lecture 1 + 2 (Week 1)

What is the difference between cognitive and biological psychology?

• Cognitive psychology: Studies mental processes and how they interact (functional/process models).

• Biological psychology: Studies the brain mechanisms underlying those processes (structural models).

• Cognitive neuroscience: Combines both approaches.

Historical and Philosophical foundations

The shift from heart-centred to brain-centred views

1. Ancient civilizations: Ancient Egyptians, Indian, and Chinese cultures regarded the heart as the seat of thought and emotion due to its continuous movement and response to emotional arousal

2. Aristotle (384-322 BCE): Maintained a heart-centred view, asserting that the brain functioned solely as a cooling radiator to tone down the passions of the heart

3. Hippocrates (460-370 BCE): Anteceded Aristotle by concluding that the brain was the true seat of emotion and intellect

4. Galen (130-200 CE): Dissected the brains of diverse species. He declared Aristotles cardiac theory absurd, noting that nature would not place the encephalon (brain) so far from the heart, nor connect all sensory nerves directly to the brain if the heart were the central processor

Historical and Philosophical foundations

The mind-body question: Dualism vs Monism

• Dualism: The philosophical belief that reality is divided into two distinct realms: physical matter (the body) and non-physical substance (the mind or soul). The mind is viewed as separate from the physical laws of the universe

• Monism: The belief that everything in the universe consists of matter and energy, and that the mind is a phenomenon entirely produced by the physical mechanisms of the nervous system. Behavioural neuroscience operates exclusively from an empirical, monistic framework

Behaviourism vs cognitive psychology

• Behaviourism: study observable behaviour and ignore the mind and mental processes (early 20th century)

• Cognitive psychology: the mind should not be ignored and can be studied experimentally (from 1960s: cognitive revolution)

How did Noam Chomsky contribute to the cognitive revolution?

Argued that complex mental processes, especially creative language production, cannot be explained by behaviourism alone. This supported studying internal mental processes.

What did Edward Tolman's experiments demonstrate?

Rats form internal cognitive maps of their environment rather than simply learning stimulus-response associations. This supports the S–O–R model, where internal mental processes influence behaviour.

What is the information-processing approach in cognitive psychology?

The mind processes information like a computer: input → mental processing → output. Cognitive processes such as attention, memory, and decision-making transform information into behaviour.

What did Sternberg (1966) discover about short-term memory scanning?

Reaction times increased by ~40 ms per additional item for both yes/no responses, supporting serial exhaustive scanning: all items are checked, even when a match is found.

The equal slopes of yes and no trials are important evidence for exhaustive scanning.

Experimental ablation by Pierre Flourens (1815)

Flourens pioneered experimental ablation by removing brain regions in animals to discover their functions, identifying areas responsible for heart rate, breathing, movement, and sensory reflexes.

Ablation vs. natural lesions:

• Experimental ablation: Controlled removal of brain tissue → supports causal conclusions.

• Natural lesions: Brain damage (e.g., stroke) → harder to interpret because multiple areas may be affected.

Discovery of Purkinje cells by Jan Purkinje (1837)

Purkinje discovered Purkinje fibers (heart-contracting muscular fibers) and used microscopic analysis to identify large, branching Purkinje cells within the cerebellum.

Effect of electrical stimulation of the brain Fritsch&Hitzig 1870

Using weak electrical currents applied to the exposed cerebral cortex of dogs, Fritsch and Hitzig discovered that stimulating specific regions induced contraction of specific muscles on the opposite (contralateral) side of the body. This region is known today as the primary motor cortex.

What did Wundt and Titchener contribute to experimental psychology?

Wundt established the first psychology laboratory (1879). Together with Titchener, he used introspection (reporting conscious experiences) to study the structure of the mind.

Why did John B. Watson reject introspection?

Introspection was subjective, unreliable and difficult to verify. Watson argued psychology should focus on observable behaviour, establishing behaviourism.

What is the difference between classical and operant conditioning?

• Classical (Pavlov/Watson): Learning associations between stimuli (e.g., bell → food).

• Operant (Skinner): Learning through consequences (rewards increase behaviour; punishment decreases it).

What is Broadbent's filter model of attention?

Attention has limited capacity. A selective filter allows attended sensory information to receive further processing, while much unattended information is filtered out.

How did Charles Darwin's theory of evolution contribute to functionalism, and how are behaviors inherited?

Darwin's theory of evolution inspired functionalism, the idea that physical structures and behaviors serve useful, adaptive functions. Behaviors are not directly inherited; instead, inherited physical structures (e.g., specialized neural circuits) generate behaviors.

How does natural selection explain the evolution of adaptive traits and behaviours?

Heritable variations that improve survival or reproduction are more likely to be passed on, making advantageous traits more common over generations.

How did Galvani's findings challenge Descartes' explanation of movement?

• Descartes: Proposed a hydraulic mechanism involving fluid flowing through nerves.

• Galvani: Showed that electrical stimulation of a frog's nerve caused muscle contraction, demonstrating the role of electricity in neuromuscular activity.

What is Müller's doctrine of specific nerve energies?

The sensation experienced depends on which sensory nerve pathway is activated, not simply how it is stimulated (e.g., optic nerve → visual sensation).

Both help explain how the understanding of nervous-system functioning developed.

What is the difference between Broca's and Wernicke's areas?

• Broca's area: Left frontal lobe; important for speech production.

• Wernicke's area: Left temporal region; important for language comprehension.

Damage can impair their respective language functions.

What did the case of Henry Molaison (H.M.) demonstrate?

Removal of medial temporal brain structures severely impaired his ability to form new long-term memories, demonstrating their importance for memory formation.

Mutations

Accidental alterations in an organisms biological blueprint in their chromosomes

Primate evolution

The key competitive traits developed by our human ancestors

1. Agile hands: facilitated tool construction and usage

2. Bipedalism: Walking upright on two limbs permitted energy-efficient long distance travel while keeping hands free to carry tools and food

3. Mastery of fire: enabled cooking, warmth, and protection against nocturnal predators

4. Symbolic language: Allowed knowledge sharing across generations and complex group coordination

What is neoteny (“extended youth”)?

in humans neoteny is our prolonged maturation (“extended youth”), allowing more brain development and experience dependent learning.

Primate brains contain significantly more neurons per gram than rodent brains

Neoteny: Prenatal division and postnatal growth

• Prenatal division: Extended cell division in utero results in a newborn brain weighing approximately 350g

• Postnatal growth: The human brain quadruples in size, reaching its adult mass of approximately 1,400g in late adolescence through glial cell proliferation, dendritic branching, and myelination. Prolonged parental care provides an developmental "apprenticeship" window for experience-dependent circuit modification.

the Institutional Animal Care and Use Committee (IACUC)

In the US, animal research receiving federal funding is governed by the IACUC

the panel includes a veterinarian, active scientists, non-scientist members, and un-affiliated community representatives

Human research ethical oversight: 3 components

1. Informed consent: Participants must be fully informed regarding the nature of the research, data collection procedures, potential risks, and anticipated benefits prior to participation

2. Institutional review board (IRB): An independent panel of scientists, laypeople, and community members that reviews human research proposals to guarantee participant protection, voluntary status, and strict data confidentiality.

3. Neuroethics: An interdisciplinary field dedicated to examining the ethical implications of neuroscience, including brain privacy (neuroimaging data), personality shifts following deep brain stimulation or brain trauma, cognitive enhancers, and the historical legacy of psychosurgery.

What does EEG measure, and what are its strengths and weaknesses?

Records electrical activity through scalp electrodes.

High temporal resolution (when activity happens), but poor spatial resolution (where it happens).

What is an ERP, and how is it obtained from EEG?

An Event-Related Potential is the brain's electrical response to a specific event, obtained by averaging time-locked EEG trials to reduce background noise.

What do PET and fMRI measure, and what are their strengths and weaknesses?

Indirectly measure brain activity through blood flow/metabolism.

High spatial resolution (where), but poor temporal resolution (when).

What is the subtraction method in brain imaging?

Subtracting brain activity during a control task from an experimental task to isolate a specific cognitive process. Both tasks should differ only in that process.

$$\text{Target Cognitive Process} = \text{Brain Activity (Experimental Task)} - \text{Brain Activity (Control Task)}$$

What did Ganis et al. (2004) discover about visual perception and mental imagery?

Both activate overlapping brain networks, but visual perception activates primary visual cortex (V1) more strongly than mental imagery.

What did Petersen et al. (1988) demonstrate using PET imaging?

Using the subtraction method, they showed that different language processes (visual word recognition, speech production, and semantic retrieval) involve different brain regions.

What is TMS, and how does it establish causality in brain research?

• TMS: Uses magnetic pulses to temporarily disrupt activity in specific brain regions.

• rTMS: Can create a temporary virtual lesion through repeated stimulation.

• Causality: Tests whether a brain region is necessary for a cognitive function, unlike EEG, fMRI, and PET, which only show correlations.

What did Kosslyn et al. (1999) demonstrate using TMS?

• Real TMS over visual cortex slowed performance in both visual perception and mental imagery, compared with sham TMS.

  Conclusion: Provides causal evidence that visual cortex contributes to mental imagery.

V1 and C1

• V1 (Primary Visual Cortex): The brain region in the occipital lobe responsible for the initial processing of visual information.

• C1 (ERP component): The earliest measurable visual brain response originating in V1, occurring approximately 50–90 msafter a stimulus.

How do ERP and fMRI findings explain the influence of spatial attention on V1?

• ERP (Luck & Ford, 1998): The earliest visual response in V1 (C1 wave) is not affected by attention.

• fMRI (Martinez et al., 1999): Shows that attention does influence activity in V1.

• Explanation: Initial visual information reaches V1 unaffected by attention. Higher brain regions then process it and send feedback signals back to V1, modifying its activity later.

• Conclusion: Attention influences V1 through later feedback, rather than during initial visual processing.

How do EEG/ERP, PET, and fMRI differ in temporal and spatial resolution?

• EEG/ERP: High temporal, low spatial resolution.

• PET: Low temporal, high spatial resolution.

• fMRI: Low temporal, high spatial resolution.

Which neuroscience methods can establish causality, and which are correlational?

• Causal: TMS/rTMS and experimental lesions (disrupt brain regions to test their necessity).

• Correlational: EEG/ERP, PET, and fMRI (measure activity without directly manipulating it).

• Behavioral RT: Measures processing speed but cannot independently establish which brain regions are necessary.

Generalisation vs. Reduction

• Generalisation looks outward to identify broad rules of behavior across situations (e.g., classifying nest building as temperature regulation vs. parental care).

• Reduction looks inward to break behavior down into biological machinery (e.g., tracing temperature sensors to hypothalamic firing).

• Exam Tip: Behavioral neuroscientists must use both concepts; reduction without generalisation leads to misinterpreting functional purpose.

Feature Search vs. Conjunction Search

• Feature Search: Parallel, immediate ("pop-out"), set size does not affect reaction time.

• Conjunction Search: Serial, item-by-item scanning, reaction time increases linearly as set size grows.

What did Wilder Penfield demonstrate through electrical brain stimulation?

Stimulating specific cortical regions produces movements, sensations, or perceptual experiences, demonstrating localization of brain functions and helping map the motor and somatosensory cortices.

What is the difference between the motor and somatosensory cortices?

• Motor cortex: Sends commands to control voluntary movements.

• Somatosensory cortex: Processes sensory information from the body.

Both have organized body maps called homunculi.

What did Helmholtz discover about nerve conduction, and why was it important?

Demonstrated that nerve impulses travel at a finite, measurable speed, rather than instantaneously. This helped establish mental chronometry (measuring the time taken by mental processes).

What is Donders' reaction-time subtraction method?

Estimates the duration of a mental process by comparing two tasks that differ only in that process.

Example: Go/no-go RT − Simple RT = Estimated stimulus discrimination time.

Limitation: Assumes the processing stages are independent and other stages remain unchanged.

What is the difference between distributed and massed practice?

• Distributed practice: Learning spread across multiple sessions → better long-term retention.

• Massed practice: Learning concentrated into long sessions → generally less efficient retention.

Baddeley & Longman (1978) demonstrated the benefits of distributed practice.

What are the generation effect and testing effect?

• Generation effect: Information is remembered better when actively generated rather than simply read (Slamecka & Graf, 1978).

• Testing effect: Retrieving information through testing improves later memory more than additional passive studying (Karpicke & Roediger, 2008).

What is the levels-of-processing theory of memory?

Deep processing (understanding meaning and making associations) produces better memory than shallow processing(focusing on appearance or sound).

Craik & Tulving (1975) found that semantic processing led to the best retention.

What did Mishkin and Ungerleider's lesion experiments demonstrate?

Damage to the inferior temporal cortex impaired object recognition, while parietal damage impaired spatial landmark discrimination. This demonstrates specialized brain functions.

What is the neuron doctrine proposed by Santiago Ramón y Cajal?

The nervous system consists of individual, separate neurons, rather than one continuous interconnected network.

What did the Posner cueing task demonstrate about spatial attention?

• Valid cue: Target at attended location → fastest RT.

• Neutral cue: No location prediction → intermediate RT.

• Invalid cue: Target at unattended location → slowest RT.

What do the main ERP components reveal about attention and language?

• C1: Earliest visual processing (~50–90 ms).

• P1/N1: Enhanced by spatial attention.

• N400: Semantic anomalies (unexpected meaning).

• P600: Syntactic anomalies (grammatical violations).

Why are ERPs useful compared with reaction times when studying cognitive processes?

• RT: Measures the final behavioural response after multiple processing stages.

• ERP: Reveals when specific cognitive processes occur.

Conclusion: ERPs provide greater insight into the timing of brain processing.

What is the main difference between PET and fMRI?

• PET: Uses radioactive tracers to measure physiological activity (e.g., metabolism/blood flow).

• fMRI: Measures changes in blood oxygenation (BOLD signal) without radioactive tracers.

Both measure neural activity indirectly.

What is converging evidence in cognitive neuroscience?

When different research methods support the same conclusion, strengthening the evidence.

Example: Brain imaging shows a region is active during imagery, while TMS demonstrates that disrupting it impairs imagery performance.

What are the independent and dependent variables in the Posner cueing task?

IV: Cue validity (valid, invalid, neutral). DV: Reaction time to detect the target.

What is the difference between overt and covert attention?

Overt attention involves eye movements; covert attention shifts without eye movements. Posner demonstrates covert attention.

What are the independent and dependent variables in a visual search task?

IVs: Set size and search type. DV: Reaction time for target detection.

How do visual-search RT slopes reveal attention?

Flat slope suggests parallel feature search; steep slope suggests serial, attention-demanding conjunction search.

What is the hemodynamic response function in fMRI?

The delayed BOLD signal change after neural activity, developing over seconds.

What were the IVs and DV in Kosslyn et al. (1999)?

IVs: Imagery vs perception, real vs sham TMS. DV: Reaction time.

What is sham TMS and why is it used?

A control procedure mimicking stimulation without the intended effective stimulation.

Why can neuroscience methods produce apparently conflicting findings?

They measure different aspects or time frames of neural activity, with different resolutions.