The Cognitive Brain

Chapter 1 1

The Cognitive Brain

Neurons: The Building Blocks of the

Brain

Structure of the Nervous System

The Peripheral Nervous System

The Cerebral Cortex

Subcortical Areas

Chapter 1 2

Neurons:

The Building Blocks of the Brain

Chapter 1 3

Chapter 1 4

Structure of the Nervous System

Chapter 1 5

Structure of the Nervous System

Chapter 1 6

The Peripheral Nervous SystemThe autonomic nervous system (ANS) is traditionally

divided into two major parts, the sympathetic and parasympathetic nervous systems. The sympathetic nervous system prepares an animal to respond more vigorously and accurately during an emergency.

– increases the heart rate (so more oxygen and nutrients are delivered to organs).

– increases the breathing rate (thus providing more oxygen)

– dilates the pupils (resulting in greater sensitivity to light).

– causes the palms of the hands to become moist (thus providing better grip).

– reduces digestive functions, including salivation (putting them “on hold”).

– relaxes the bladder (suspending another function that isn’t crucial in an emergency).

Chapter 1 7

The Cerebral Cortex

Chapter 1 8

Chapter 1 9

Chapter 1 10

Chapter 1 11

Chapter 1 12

Chapter 1 13

Chapter 1 14

Subcortical Areas

Chapter 1 15

Chapter 1 16

Chapter 1 17

Chapter 1 18

Chapter 1 19

Studying Cognition

Converging Evidence for Dissociations and AssociationsBehavioral Methods

Correlational Neural Methods: The Importance of Localization

Causal Neural Methods

Modeling

Neural-Network Models

Chapter 1 20

Converging Evidence for Dissociations and Associations

Converging evidence: different types of results that imply the same conclusion, lies at the heart of successful investigations in cognitive psychology.

Many of the methods in cognitive psychology are used to accomplish two general types of goals:

Dissociation: to establish that an activity or a variable affects the performance of one task (or aspect of one task) but not of another.

Double dissociation: an activity or variable affects one process but not another and a second activity or variable has the reverse properties.

Association: occurs when the effects of an activity or variable on one task are accompanied by effects on another task.

Chapter 1 21

Behavioral Methods

A behavioral method measures directly observable behavior such as the time to respond or the accuracy of a response. Researchers attempt to draw inferences about internal representation and processing from such directly observable responses.

Chapter 1 22

Chapter 1 23

Correlational Neural Methods: The Importance of Localization

Cognitive psychology has become extraordinarily exciting during the past decade because researchers have developed relatively inexpensive, high-quality methods for assessing how the human brain functions. These methods are correlational: although they reveal the pattern of brain activity that accompanies information processing, they do not show that activation in specific brain areas actually results in the task’s being carried out.

Correlation does not necessarily imply causation.

Chapter 1 24

Correlational Neural Methods: The Importance of Localization

We can evaluate the various correlational neural methods on four dimensions:

(1) Spatial resolution, how precisely they localize the brain area that produces a signal.

(2) Temporal resolution, how precisely they track changes in brain activity over time.

(3) Invasiveness, the degree to which they require introduction of foreign substances into the brain.

(4) Cost, both for the equipment (and any special facilities) and for its use in each participant test. The three most important neuroimaging.

Chapter 1 25

Correlational Neural Methods: The Importance of Localization

Chapter 1 26

A PET scan in progress.

An fMRI scan in progress.

Chapter 1 27

Causal Neural Methods