Searching Through Alternating Sequences: Working Memory and Inhibitory Tagging Mechanisms Revealed Using the MILO...

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human Factors

Background:

• Visual search efficiency is crucial for many tasks.
• The Trail Making Test (TMT) assesses cognitive flexibility and executive function.
• TMT-A (sequential) and TMT-B (alternating) differ in task demands, with TMT-B typically showing longer completion times.

Purpose of the Study:

• To investigate the cognitive mechanisms underlying visual search in sequential versus alternating conditions.
• To compare search patterns in the Multi-Item Localisation (MILO) task with TMT-A and TMT-B.
• To elucidate the role of inhibitory tagging in visual search performance.

Main Methods:

• Participants performed the MILO task with visual search through letter and digit sequences.
• Trials were blocked into 'Sequential' (letters then digits) and 'Mixed' (alternating letters and digits) conditions.
• Target visibility after selection was manipulated (vanished or remained visible).

Main Results:

• Reaction times in Mixed blocks showed a saw-tooth pattern, indicative of searching for successive target pairs.
• In Sequential blocks, reaction times were similar whether targets vanished or remained visible.
• In Mixed blocks, reaction time patterns diverged between vanish and remain conditions, suggesting impaired inhibitory tagging.

Conclusions:

• Alternating search (Mixed blocks) engages different cognitive processes than sequential search (Sequential blocks).
• The observed saw-tooth pattern and divergence in Mixed blocks suggest a breakdown in inhibitory tagging, hindering the ability to ignore previously selected targets.
• These findings provide a potential explanation for the increased difficulty and completion times associated with TMT-B compared to TMT-A.