How does cognitive load influence speech perception? An encoding hypothesis.

Area of Science:

• Cognitive Psychology
• Auditory Neuroscience
• Human Perception

Background:

• Cognitive load impacts various cognitive functions, but its effect on speech perception, especially from modular tasks like face processing, is not fully understood.
• Previous research suggests cognitive load can hinder speech perception, but the specific conditions and underlying mechanisms require further investigation.

Purpose of the Study:

• To investigate how cognitive load, induced by face processing, affects speech perception acuity.
• To determine if concurrent encoding of visual stimuli (faces) with auditory stimuli (speech) interferes with speech perception.
• To explore the role of working memory encoding as a potential locus of interference.

Main Methods:

• Two experiments utilized a four-interval oddity speech perception task.
• Cognitive load was manipulated using a face-memory task, with variations in simultaneous encoding.
• A visual search task was included as a reference condition known to affect speech perception.

Main Results:

• Experiment 1 showed no significant impairment in speech perception under face-memory load when faces were presented before speech.
• Experiment 2 demonstrated decrements in speech perception when face encoding occurred concurrently with speech stimuli.
• Both concurrent face processing and a visual search task led to reduced speech perception performance.

Conclusions:

• Speech perception can be affected by cognitive loads from tasks previously considered modular.
• Concurrent encoding in working memory appears critical for observing interference in speech perception.
• Working memory encoding is a likely site where cognitive load interferes with speech perception processes.