Brain and Neuropsychology

The Structure of the Human Brain

  • Weight: 1.4 kg, largest in relation to body size in animal kingdom.

  • Function: Controls various functions (e.g., breathing, sensory perception).

  • Division: Left and right hemispheres, connected through the brainstem.

Key Components

  • Cerebrum: Largest part, responsible for higher processes; includes the cortex.

  • Cortex: Outer layer with folds (gyri) and creases (sulci) to maximize surface area for nerve cells.

Functions of the Brain

  • Cortex Areas: Specialization for distinct functions; research indicates a more dispersed functionality.

Major Lobes and Their Functions

  • Frontal Lobe: Decision-making, impulse control, motor control.

  • Temporal Lobe: Hearing, speech processing, memory functions.

  • Parietal Lobe: Perception, touch sensations, face recognition.

  • Occipital Lobe: Vision and visual processing.

  • Cerebellum: Coordination, balance, information integration.

Study: Damasio et al. (1994) - Phineas Gage

  • Background: 1848 incident with frontal lobe damage leading to personality changes.

  • Aim: Investigate damage areas in Gage's skull.

Method

  • Procedure: 3D modeling of skull damage to determine iron rod's path.

Results

  • Damage likely in right and left hemispheres of the frontal lobe, especially the ventromedial region.

Conclusion

  • Ventromedial frontal lobes: Important for decision-making and impulse control. Evidence from similar case studies supports findings.

Evaluating the Study

  • Strengths: Use of modern technology, better behavioral predictions post-frontal lobe damage.

  • Limitations: Reliability of historical data, generalization issues in case studies.

Lateralisation of Function

  • Asymmetry: Different roles for each hemisphere; left hemisphere controls right body side and vice-versa.

  • Corpus Callosum: Connects hemispheres for communication.

Left vs Right Hemisphere

  • Left Hemisphere: Language processing (Broca's area), verbal abilities.

  • Right Hemisphere: Spatial awareness, creativity, visual perception.

Sex Differences in Brain Lateralisation

  • Females: Better language skills, thicker corpus callosum; uses both hemispheres.

  • Males: Better at spatial tasks; more unilateral hemisphere activity.

Evaluating Sex Differences

  • Strengths: Empirical evidence supports differences in brain structure and function.

  • Limitations: Conflicting findings and weaknesses in research methodology.

Study: Sperry (1968) - Split-Brain Research

  • Background: Split-brain surgery for epilepsy patients.

  • Aim: Investigate effects of split-brain on information processing.

Method

  • Participants: 11 split-brain patients, performing tasks involving sensory information processing.

Results

  • Each hemisphere can function independently with distinct abilities; left-hand responses are harder to verbalize.

Conclusion

  • Supports Lateralisation Theory; highlights distinct functions of left and right hemispheres.

Synaptic Functioning and Neurological Damage

  • Synaptic Transmission: Process of neurotransmitter signal transfer.

  • Impact of Neurological Damage: Interruption in message passing due to nerve damage; significant effects on behavior; disorders can arise.

Damage to Pre-frontal Cortex

  • Affects impulse control and emotions; linked to aggressive behaviors and criminal tendencies.

Changes in Psychology Over Time

  • Evolved from philosophy to a scientific discipline focusing on neuroscience.

  • Historical emphasis on anatomy transitioned to behavioral connections through modern imaging techniques (EEG, MRI, PET).

  • Contemporary methods allow for precise exploration of brain behavior relationships at the neural level.