Raoul Bell

Age-related differences in irrelevant-speech effects.

Three experiments examined age-related differences in irrelevant-speech effects. Younger and older adults were required to recall short prose texts or lists of semantically related words presented visually together with distractor speech. In all experiments, older adults made more semantically related intrusion errors from the irrelevant speech than younger adults. Results of a source memory test suggested that these age-related differences in interference are most likely due to both inhibitory deficits and source-monitoring problems. The results lend partial support to the inhibition deficit theory of cognitive aging.

Equivalent irrelevant-sound effects for old and young adults

Three experiments are reported in which a total of 182 old and 193 young adults recalled sequences of digits presented visually in silence or accompanied by office noise. In each experiment, an effect of irrelevant sound was found—that is, a reduction of serial recall due to auditory distraction. Old adults exhibited poorer serial recall than did young adults, but the irrelevant-sound effect was equivalent in both age groups. This was true even though the sound level of the irrelevant sound was adjusted to each individual’s hearing capability, and the effect remained whether or not the difficulty of the serial recall task was equated across age groups. These results are problematic for the inhibitory deficit theory of cognitive aging, which predicts that old adults should be more susceptible to auditory distraction than are young adults.

Habituation of the Irrelevant Sound Effect: Evidence for an Attentional Theory of Short-Term Memory Disruption.

Immediate serial recall is seriously disrupted by to-be-ignored sound. According to the embedded-processes model, auditory distractors elicit attentional orienting that draws processing resources away from the recall task. The model predicts that interference should be attenuated after repeated exposure to the auditory distractors. Previous failures to observe evidence for habituation can be explained by assuming that habituation to complex distractor features depends on the availability of working memory resources. Here we demonstrate that the irrelevant sound effect is attenuated after passive listening to the auditory distractors during a preexposure phase prior to the serial recall task. Experiment 1 shows that the irrelevant sound effect is abolished after 20 min of passive listening to the distractor speech. Experiments 2-4 show that irrelevant sound interference is significantly reduced after listening to distractors for 45 s. As predicted by the habituation hypothesis, an attenuation of interference occurs only when the distractor material matches the material played in the preexposure phase (Experiment 5). The results support an attentional conceptualization of the irrelevant sound effect.

Enhanced old―new recognition and source memory for faces of cooperators and defectors in a social-dilemma game

A popular assumption in evolutionary psychology is that the human mind comprises specialized cognitive modules for social exchange, including a module that serves to enhance memory for faces of cheaters. In the present study, participants played a trust game with computerized opponents, who either defected or cooperated. In a control condition, no interaction took place. In a surprise memory test, old-new recognition for faces and source memory for the associated cooperative or non-cooperative behavior were assessed. A multinomial model was used to measure old-new discrimination, source memory, and guessing biases separately. Inconsistent with the assumption of a memory mechanism that focuses exclusively on cheating, the present study showed enhanced old-new discrimination and source memory for both cooperators and defectors. Rarity of the behavior strategies within the experiment modulated source memory, but only when the differences in base rates were extreme. The findings can be attributed to a mechanism that focuses on exchange-relevant information and flexibly adapts to take into account the relative significance of this information in the encoding context, which may be more beneficial than focusing exclusively on cheaters.

The role of habituation and attentional orienting in the disruption of short-term memory performance

A series of experiments explored habituation and dishabituation to repeated auditory distractors. Participants memorised lists of visually presented items in silence or while ignoring continuously presented auditory distractors. No habituation could be observed, in that the size of the auditory distractor effect did not decrease during the experiment. However, there was evidence for attentional orienting when novel auditory material was presented after a long period of repetitive stimulation, in that a change of distractors was associated with a temporary decrease in recall performance. The results are most consistent with theoretical accounts that claim that the auditory distractor effect is caused primarily by automatic interference, but that still allow attention to play a limited role in the short-term maintenance of information.

ERP correlates of the irrelevant sound effect

The irrelevant sound effect refers to a decrement in serial-recall performance when auditory distractors are played during encoding or retention of the to-be-remembered items. We examined the event-related brain potentials (ERPs) that were elicited in response to the auditory distractors during encoding and retention of visually presented target sequences. Changing-state distractor sequences that consisted of several different distractor items interfered more with serial recall than steady-state sequences that consisted of repetitions of a single distractor item. The ERP responses that were elicited in response to the distractors comprised the exogenous N1 component and were further characterized by a subsequent positive wave, and a late negativity. The changing-state effect was associated with an increased N1 and a P3a. The results support the attention-capture account of the irrelevant sound effect.

Valence modulates source memory for faces

Previous studies in which the effects of emotional valence on old-new discrimination and source memory have been examined have yielded highly inconsistent results. Here, we present two experiments showing that old-new face discrimination was not affected by whether a face was associated with disgusting, pleasant, or neutral behavior. In contrast, source memory for faces associated with disgusting behavior (i.e., memory for the disgusting context in which the face was encountered) was consistently better than source memory for other types of faces. This data pattern replicates the findings of studies in which descriptions of cheating, neutral, and trustworthy behavior were used, which findings were previously ascribed to a highly specific cheater detection module. The present results suggest that the enhanced source memory for faces of cheaters is due to a more general source memory advantage for faces associated with negative or threatening contexts that may be instrumental in avoiding the negative consequences of encounters with persons associated with negative or threatening behaviors.

Self-relevance increases the irrelevant sound effect: Attentional disruption by one's own name

Memory performance is severely disrupted when task-irrelevant sound is played during item presentation or in a retention interval. Working memory models make contrasting assumptions on whether the semantic content of the auditory distractors modulates the irrelevant sound effect. In the present study, participants made more errors in serial recall when they had to ignore sentences containing their own name as opposed to that of a yoked-control partner. These results are only consistent with working memory models that allow for attentional processes to play a role in the explanation of the irrelevant sound effect. With repeated presentation the disruptive effect of ones own name decreased, whereas the disruptive effect of the auditory distractors in the control condition remained constant. The latter finding is most consistent with the duplex model of auditory attention, which assumes that the irrelevant sound effect is primarily caused by automatic interference of acoustic distractor features, but at the same time allows for a disruption of encoding due to attentional capture by unexpected deviants. However, to explain the present results, the mechanism responsible for the attentional capture has to be extended to highly (self-)relevant auditory distractors.

Is the survival-processing memory advantage due to richness of encoding?

Memory for words rated according to their relevance in a grassland survival context is exceptionally good. According to Nairne, Thompson, and Pandeiradas (2007) evolutionary-based explanation, natural selection processes have tuned the human memory system to prioritize the processing of fitness-relevant information. The survival-processing memory advantage has been replicated numerous times, but very little is known about the proximate mechanisms behind it. The richness-of-encoding hypothesis (Kroneisen & Erdfelder, 2011) implies that rating the usefulness of items in a survival context leads to the generation of a large number of ideas that may be used as retrieval cues at test to boost recall. In Experiment 1, the typical survival-processing recall advantage was obtained when words were rated according to their usefulness in 1 of 3 fictional contexts. In Experiment 2, participants were asked to write down any ideas that came to mind when thinking about the usefulness of the words. Consistent with the richness-of-encoding hypothesis, participants generated more ideas in the survival condition than in the fitness-irrelevant control conditions. In Experiment 3, participants generated more ideas for congruent than for incongruent words, demonstrating that the richness-of-encoding hypothesis can also account for the previously obtained congruency effect on recall (Butler, Kang, & Roediger, 2009). In both experiments the number of ideas written down predicted future recall performance well. Our results provide further evidence for the assumption that richness of encoding is an important proximate mechanism involved in memory performance in the survival-processing paradigm.

On the flexibility of social source memory : A test of the emotional incongruity hypothesis

A popular hypothesis in evolutionary psychology posits that reciprocal altruism is supported by a cognitive module that helps cooperative individuals to detect and remember cheaters. Consistent with this hypothesis, a source memory advantage for faces of cheaters (better memory for the cheating context in which these faces were encountered) was observed in previous studies. Here, we examined whether positive or negative expectancies would influence source memory for cheaters and cooperators. A cooperation task with virtual opponents was used in Experiments 1 and 2. Source memory for the emotionally incongruent information was enhanced relative to the congruent information: In Experiment 1, source memory was best for cheaters with likable faces and for cooperators with unlikable faces; in Experiment 2, source memory was better for smiling cheater faces than for smiling cooperator faces, and descriptively better for angry cooperator faces than for angry cheater faces. Experiments 3 and 4 showed that the emotional incongruity effect generalizes to 3rd-party reputational information (descriptions of cheating and trustworthy behavior). The results are inconsistent with the assumption of a highly specific cheater detection module. Focusing on expectancy-incongruent information may represent a more efficient, general, and hence more adaptive memory strategy for remembering exchange-relevant information than focusing only on cheaters.