Ghosts in the machine: memory interference from the previous trial

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• Proactive interference impairs new memory formation.
• Previous studies used categorical tasks, limiting detailed analysis.

Purpose of the Study:

• Investigate proactive interference in a spatial memory task.
• Characterize the temporal and spatial profile of this interference.
• Compare behavioral findings with attractor network models.

Main Methods:

• Trained five macaques in a spatial delayed response task with continuous memoranda.
• Analyzed oculomotor responses to measure memory bias.
• Simulated results using attractor network models of working memory.

Main Results:

• Memory in the current trial was biased towards the previous trial's memorandum location.
• This bias magnitude increased with the current memory period duration.
• Standard attractor models replicated the spatial bias but not its temporal profile.

Conclusions:

• Behavioral data suggests a two-component memory system: a rapidly decaying visual store and a sustained, interference-prone store.
• Attractor network models may need modification to fully capture proactive interference dynamics.