The influence of concurrent load on mouthed and vocalized modality effects

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human Memory

Background:

• Modality effects in memory refer to differences in recall based on sensory input (e.g., auditory vs. visual).
• The automaticity of these effects, particularly those related to speech production (vocalizing, mouthing), is not fully understood.
• Preattentive processes are those that occur automatically and without conscious awareness.

Purpose of the Study:

• To investigate whether modality effects from vocalizing and silent mouthing are automatically activated preattentive processes.
• To determine if concurrent task demands influence the magnitude of these modality effects.

Main Methods:

• A visual search task was combined with a serial word recall task.
• Participants engaged in vocalizing or silent mouthing of words during recall.
• Concurrent task demands were manipulated by having participants simultaneously search for digits.

Main Results:

• Serial position functions, which describe recall accuracy across list positions, systematically changed with increased concurrent task demands.
• Crucially, the magnitude of the modality effect for both vocalizing and silent mouthing remained unchanged despite the increased task demands.
• This indicates that the modality effect is robust to interference from concurrent tasks.

Conclusions:

• Modality effects, whether from spoken words or speech-related gestures like mouthing, appear to index an automatically activated preattentive process.
• These findings suggest that the brain automatically processes information based on modality, even when attention is divided.
• The automatic nature of modality effects has implications for understanding information processing and memory encoding.