bio psych2 1

Lecture Overview

Biological Psychology 2 - Lecture 01The Brain and CognitionDr. Richárd ReichardtEmail: reichardt.richard@ppk.elte.hu

Understanding Biological Psychology

Biological psychology seeks to explore the biological foundations of behavior and cognition. Behavior refers to observable actions performed by humans and animals, while cognition encompasses all mental processes. The interplay between these aspects is heavily influenced by the activities of the brain.

Definition of Biological Psychology

Also known as behavioral neuroscience, biological psychology (or biopsychology) applies biological principles to examine physiological, genetic, and developmental factors that shape behavior in humans and other species. This field emphasizes the links between biological systems and psychological processes.

Core Assumptions of Neuroscience

The foundational premise of neuroscience is that the brain is the source of mental phenomena and behavior, suggesting that understanding the brain's mechanisms is essential for deciphering psychological functions.

Levels of Organization in Neuroscience

Neuroscience categorizes the brain's structure into various levels of organization, including:

• Systems

• Regions

• Circuits

• Cells

• Synapses

• MoleculesEach level provides a distinct perspective on how biological processes drive cognition and behavior.

Approaching Cognitive Neuroscience

To fully grasp the mind's complexities, scientists take an integrated approach that examines the brain's structure, a method known as cognitive neuroscience. This entails assessing biological organization at varying levels, from molecular to systems-level analyses.

The Structure of Neurons

The brain consists primarily of neurons, which are specialized cells responsible for processing and transmitting signals. Neurons are equipped with processes called dendrites (receiving signals) and axons (sending signals) that create complex networks to facilitate communication.

Signal Generation and Propagation

Historical research dating back to the 18th century revealed that neurons can generate and propagate electrical signals, essential for initiating muscle contractions and other bodily responses.

Mechanisms of Signal Propagation

Neurons transmit signals to adjacent neurons via a cascade of neurotransmitters, which are chemicals released that induce similar electrical signals in subsequent neurons within a network.

Action Potentials

The electrical signals generated by neurons, termed action potentials, arise from the movement of charged particles across the neuronal membrane. This physiological process enables the transmission of information between neurons.

Characteristics of Action Potentials

An action potential is characterized by a temporary alteration in a neuron's membrane potential, lasting approximately 1-2 milliseconds, commonly referred to as a "spike" in electrophysiological contexts.

Neural Coding

Information representation in neurons primarily hinges on the frequency of action potentials rather than their amplitude, which remains constant. For instance, the rate of action potentials may vary in response to different intensities of stimuli (e.g., pressure), allowing neurons to encode diverse sensory information.

Discovery of Feature Detectors

In the 1960s, researchers Hubel and Wiesel identified specific neurons in the visual cortex of cats that respond preferentially to particular contrast patterns within the visual field. This discovery exemplifies how certain neurons are specialized in encoding specific low-level visual features.

Neural Representations

Contemporary neuroscience posits that distinct patterns of neural activity correspond to specific cognitive states, raising intriguing questions about how neural patterns can encapsulate the breadth of human experiences.

Location of Neural Representations

Neural coding sheds light on how information is represented in the brain, but it also raises inquiries about the spatial distribution of these representations. Classic examples include Broca's and Wernicke's areas, which are known to handle language processing.

Functional Magnetic Resonance Imaging (fMRI)

fMRI technology enables researchers to visualize brain activity during various cognitive tasks. It reveals specific brain regions activated by distinct stimuli, such as the parahippocampal place area for spatial navigation and the extrastriate body area for human body recognition.

Understanding Distributed Representation

A fundamental principle of cognition is that most experiences are multidimensional. For instance, perceiving a face activates multiple brain areas, indicating that cognitive processes rely on intricate networks of neural structures, termed distributed representation.

Functional Connectivity in Brain Networks

To ascertain the functional networks involved in representing multidimensional stimuli, researchers employ advanced fMRI data analyses to identify functional connectivity. This approach examines how correlated brain regions synchronize their activity during specific tasks.

Examples of Functional Connectivity

Research has highlighted variances in connectivity among different brain areas, such as high correlation between motor and somatosensory regions versus poor correlation between motor and visual regions—indicating specialized interconnections and processing streams within the brain.

The Default Mode Network (DMN)

The discovery of the default mode network (DMN) represents a significant finding in functional connectivity research, showing that groups of cortical areas activate simultaneously during restful states or when individuals are not engaged in active tasks, underscoring the brain's baseline activity patterns.

Closing Remarks

Thank you for your attention! In the next class, we will dive into Consciousness and Attention.