levels of sensory processing somatosensory cortex face hand arm

Levels of Sensory Processing

Somatosensory Cortex

FaceHand Arm

Attention!!

fMRI images of a subject cued to expect a stimulus in a particular portion of the visual field show right hemisphere activation in the

cingulate cortex.

What is attention??

• Traditional information processing views: Based on limits to simultaneous processing.

• Mechanisms exist to filter, gate, select or inhibit.

• Prevailing view for years: Bottleneck

• A basic conversion from massive parallel input to a limited or serial processing mode.

Sequel to information processing:

• Hi degree of parallel processing

• Flexible allocation of resources

• Attention interacts with motor output.

Along came Posner and Boies

• Attention is not a unitary phenomenon.

• Alertness or Readiness to take in information (concentration, vigilence)

• Selective Attention – search a display or an environment for a particular target.

A. SPATIAL ATTENTION (3 components). Covert and overt.

“Attentional Stimuli”

• Are responded to more rapidly

• Give rise to an increase or a decrease in neuronal responses

• Have signature ERPs (P300, N200, N400)

• Can be reported with a lower threshold of occurence

• Will be remembered better

Attentional Stimuli - continued

• Increased learning of the stimulus

• A bias to respond to that stimulus

• Note – many behavioral indications involve change in accuracy and latency. The pattern of change is taken as an indication of attention or NOT.

Impaired Response Inhibition

• Stroop

Green

Yellow

Red

Purple

Blue

Red

Black

Yellow

Orange

Blue

Purple

Red

Green

Black

Blue

Yellow

Green

Red

Purple

Blue

Blue

Brown

Blue

Red

Green

Green

Yellow

Red

Yellow

Orange

Blue

Red

Green

Yellow

Black

Yellow

Orange

Red

Purple

Blue

Purple

Red

Green

Black

Blue

Yellow

Green

Red

Purple

Blue

Green

Yellow

Red

Yellow

Orange

Blue

Brown

Blue

Red

Green