Neuroplasticity of the Brain

Theory

• Brain's ability to rearrange connections between neurons.
• Structural changes in the brain from learning or experience.
• High levels of stimulation and learning opportunities lead to increased neural connections.
• Dendritic Branching: Neurons connect to create new traces in the brain when we learn something new.

Key Terms

Neural Pruning

• Unused synapses fade; frequently used synapses strengthen.
• Influenced by environmental factors.

Neural Networks

• Develop by making and breaking synaptic connections.
• Can change developmentally, over time, or post-injury.

Neuroplasticity

• Brain's ability to change in response to experiences, learning, environmental influences.
• Involves modifying neuron structure, connections, and networks.

Neural Transmission

• Nerve impulses travel along neurons to reach synapses.

Draganski et al (2004) Study

Aim

• Investigate the relationship between neuroplasticity and learning via juggling training effects.

Procedure

• 24 participants (21 females, 3 males) non-jugglers initially.
• Baseline MRI scan for brain structure and grey matter.
• Participants divided into juggling group (training for 3 months) and control group.
• MRI scans at 3 months and 6 months (no practice during later period).

Findings

• Juggling group: significant grey matter volume increase in mid-temporal area (visual processing, spatial perception).
• fMRI: Increased activation in mid-temporal area and posterior parietal cortex.
• 3-month scan: Increased neural connection, dendritic branching.
• 6-month scan: Reduced grey matter due to neural pruning.
• Control group showed no such changes.

Conclusions

• Learning leads to structural brain changes and increased synaptic connections.
• Evidence of neuroplasticity's role in adapting to experience and repetition.

Rosenzweig, Bennett, and Diamond (1972) Study

Aims

• Study the influence of environmental factors on brain neuroplasticity.

Procedure

• Rats placed in enrichment (social, stimulating) or deprivation (isolated) environments.
• Brain structures analyzed post-mortem after 30 or 60 days.

Results

• Enriched environment rats had increased cortex thickness and dendritic branching.
• Frontal lobe heavier in enriched environment rats.

Conclusions

• Environmental enrichment impacts brain development and cognitive function.
• Supports increased synaptic connections from stimulation.

Applications of Neuroplasticity

• Rehabilitation and Recovery: Key in post-brain injury therapies to reorganize neural connections.
• Learning and Education: Techniques promoting neuroplasticity improve learning and retention.
• Cognitive Enhancements: Brain training programs leverage neuroplasticity for memory and skills development.

Strengths and Weaknesses

Strengths

• Methodology: Longitudinal design shows changes over time; MRI and non-invasive procedures are safe.
• Ethics: Informed consent, confidentiality, and safety in human studies.

Weaknesses

• Alternate Explanations: Physical exercise might cause brain changes, not just learning.
• Sample Size: Small and gender-biased, limits generalizability.
• Ethics in Animal Studies: Use of animals raises ethical concerns.

Overall Evaluation of Neuroplasticity

Testability

• Testable with brain scans (MRI) for structural changes and synaptic connections.

Evidence

• Multiple studies show consistent results, supporting neuroplasticity theory.

Construct Validity

• Clearly defined processes (dendritic branching and pruning) and reliably measured with consistent results.

Unbiased

• Applies to all races, genders, and ages, though ability to develop skills declines with age.

Predictability

• Explains loss of skills through neural pruning and relearning through new neural connections.