The continuous performance test, identical pairs version (CPT-IP): III. Brain functioning during performance of...

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Psychiatric Research

Background:

• The Conners' Continuous Performance Test-Identical Pairs (CPT-IP) uses number and shape subtasks to assess independent attentional skills.
• Previous research suggests these subtasks may reveal lateralized attentional performance differences, potentially differentiating psychiatric conditions like schizophrenia and major depression.

Purpose of the Study:

• To investigate the hypothesis that the CPT-IP's Numbers and Shapes subtasks engage distinct, lateralized brain regions.
• To explore how these subtasks affect cerebral blood flow patterns using SPECT imaging in healthy individuals.

Main Methods:

• Seven healthy subjects underwent SPECT scans during performance of the CPT-IP Numbers and Shapes subtasks.
• Subtasks were administered in a counterbalanced order, with scans performed after 10 minutes of task engagement.
• Quantitative analysis of regional cerebral blood flow was conducted using a semi-automated region of interest (ROI) approach on SPECT data.

Main Results:

• The Numbers task showed increased left-sided activity in anterior subcortical regions (anterior cingulate, frontal white matter, basal ganglia) and the left thalamus.
• The Shapes task demonstrated more extensive bilateral perfusion in occipital regions compared to the Numbers task.
• Task-specific lateralization patterns were observed, primarily driven by changes in left-sided brain activity.

Conclusions:

• Subtle variations in stimulus parameters between the Numbers and Shapes tasks lead to distinct brain activation patterns.
• The Numbers task appears to more effectively activate anterior attention networks, potentially offering better discrimination in clinical populations.
• These findings highlight the utility of the CPT-IP subtasks in probing specific aspects of attentional networks and their lateralization.