Auditory negative priming endures response modality change; prime response retrieval does not

Target enhancement but not distractor suppression in auditory neural tracking during continuous speech

Selective attention modulates the neural tracking of speech in auditory cortical regions. It is unclear whether this attentional modulation is dominated by enhanced target tracking, or suppression of distraction. To settle this long-standing debate, we employed an augmented electroencephalography (EEG) speech-tracking paradigm with target, distractor, and neutral streams. Concurrent target speech and distractor (i.e., sometimes relevant) speech were juxtaposed with a third, never task-relevant speech stream serving as neutral baseline. Listeners had to detect short target repeats and committed more false alarms originating from the distractor than from the neutral stream. Speech tracking revealed target enhancement but no distractor suppression below the neutral baseline. Speech tracking of the target (not distractor or neutral speech) explained single-trial accuracy in repeat detection. In sum, the enhanced neural representation of target speech is specific to processes of attentional gain for behaviorally relevant target speech rather than neural suppression of distraction.

The persisting influence of unattended auditory information: Negative priming in intentional auditory attention switching

We studied negative priming (NP) in auditory attention switching. In a cued variant of dichotic listening, two spoken number words were presented, one to each ear, one spoken by a female, and one spoken by a male voice. A visual cue indicated whether the male or female voice was the target. A numerical magnitude judgement of the target number was required. The selection criterion could either switch or repeat across trials, so there were attention switch and repetition trials. Two experiments examined NP (distractor becomes target) and also included a "competitor priming" (CP) condition (target becomes distractor), relative to a "no priming" condition (target and distractor not related to previous trial). In Experiment 1, we investigated the basic priming effects. In Experiment 2, we additionally varied the response-cue interval (RCI; 100 ms vs. 1,900 ms) to examine time-related changes in priming. We found longer response times (RT) for switch trials compared with repetition trials (attention switch costs)-that is, when the internal processing context changed. In addition, we found longer RT for NP trials as well as reduced switch costs in long RCI, suggesting that previously relevant attentional settings dissipate over longer time. However, NP was not influenced by attention switches, and it was also not affected by RCI. Hence, NP in auditory attention switching does not seem strongly context or time sensitive.

From hands to feet: Abstract response representations in distractor-response bindings

Evidence suggests that, when people respond to target stimuli, distractors that accompany the target become integrated with the response, and can thus subsequently serve as a retrieval cue of that response-an example of distractor-response binding. In two experiments, we investigated whether the response codes that become part of such distractor-response bindings are effector-specific or abstract. In a prime-probe design, participants gave left and right responses with their hands or their feet. The required effector set was systematically varied between prime and probe responses. If participants executed each response immediately, effects of distractor-response binding were only observed for effector repetitions but not for effector changes. However, distractor-response binding was observed in effector-change trials if participants were keeping the prime-action plan active during probe-response execution. These results indicate that it is rather abstract response codes that are integrated with distractor stimuli and retrieved upon distractor repetition.

On the robustness of prime response retrieval processes: evidence from auditory negative priming without probe interference

Visual negative priming has been shown to depend on the presence of probe distractors, a finding that has been traditionally seen to support the episodic retrieval model of negative priming; however, facilitated prime-to-probe contingency learning might also underlie this effect. In four sound identification experiments, the role of probe distractor interference in auditory negative priming was investigated. In each experiment, a group of participants was exposed to probe distractor interference while another group ran the task in the absence of probe distractors. Experiments 1A, 1B, and 1C varied in the extent to which fast versus accurate responding was required. Between Experiments 1 and 2, the spatial cueing of the to-be-attended ear was varied. Whereas participants switched ears from prime to probe in Experiment 1, they kept a stable attentional focus throughout Experiment 2. For trials with probe distractors, a negative priming effect was present in all experiments. For trials without probe distractors, the only ubiquitous after-effect of ignoring a prime distractor was an increase of prime response errors in ignored repetition compared to control trials, indicating that prime response retrieval processes took place. Whether negative priming beyond this error increase was found depended on the stability of the attentional focus. The findings suggest that several mechanisms underlie auditory negative priming with the only robust one being prime response retrieval.

Spatial and identity negative priming in audition: evidence of feature binding in auditory spatial memory

Two experiments are reported with identical auditory stimulation in three-dimensional space but with different instructions. Participants localized a cued sound (Experiment 1) or identified a sound at a cued location (Experiment 2). A distractor sound at another location had to be ignored. The prime distractor and the probe target sound were manipulated with respect to sound identity (repeated vs. changed) and location (repeated vs. changed). The localization task revealed a symmetric pattern of partial repetition costs: Participants were impaired on trials with identity-location mismatches between the prime distractor and probe target-that is, when either the sound was repeated but not the location or vice versa. The identification task revealed an asymmetric pattern of partial repetition costs: Responding was slowed down when the prime distractor sound was repeated as the probe target, but at another location; identity changes at the same location were not impaired. Additionally, there was evidence of retrieval of incompatible prime responses in the identification task. It is concluded that feature binding of auditory prime distractor information takes place regardless of whether the task is to identify or locate a sound. Instructions determine the kind of identity-location mismatch that is detected. Identity information predominates over location information in auditory memory.