scholarly journals Individual differences show that only some bats can cope with noise-induced masking and distraction

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10551
Author(s):  
Dylan G.E. Gomes ◽  
Holger R. Goerlitz

Anthropogenic noise is a widespread pollutant that has received considerable recent attention. While alarming effects on wildlife have been documented, we have limited understanding of the perceptual mechanisms of noise disturbance, which are required to understand potential mitigation measures. Likewise, individual differences in response to noise (especially via perceptual mechanisms) are likely widespread, but lacking in empirical data. Here we use the echolocating bat Phyllostomus discolor, a trained discrimination task, and experimental noise playback to explicitly test perceptual mechanisms of noise disturbance. We demonstrate high individual variability in response to noise treatments and evidence for multiple perceptual mechanisms. Additionally, we highlight that only some individuals were able to cope with noise, while others were not. We tested for changes in echolocation call duration, amplitude, and peak frequency as possible ways of coping with noise. Although all bats strongly increased call amplitude and showed additional minor changes in call duration and frequency, these changes could not explain the differences in coping and non-coping individuals. Our understanding of noise disturbance needs to become more mechanistic and individualistic as research knowledge is transformed into policy changes and conservation action.

Author(s):  
Dylan G.E. Gomes ◽  
Holger R. Goerlitz

AbstractAnthropogenic noise is a widespread pollutant that has received considerable recent attention. While alarming effects on wildlife have been documented, we have limited understanding of the perceptual mechanisms of noise disturbance, which are required to understand potential mitigation measures. Likewise, individual differences in response to noise (especially via perceptual mechanisms) are likely widespread, but lacking in empirical data. Here we use echolocating bats, a trained discrimination task, and experimental noise playback to explicitly test perceptual mechanisms of noise disturbance. We demonstrate high individual variability in response to noise treatments and evidence for multiple perceptual mechanisms. Additionally, we highlight that only some individuals are able to cope with noise, while others are not. We tested for changes in echolocation call duration, amplitude, and peak frequency as possible ways of coping with noise. Although all bats strongly increased call amplitude and showed additional minor changes in call duration and frequency, these changes cannot explain the differences in coping and non-coping individuals. Our understanding of noise disturbance needs to become more mechanistic and individualistic as research knowledge is transformed into policy changes and conservation action.


2019 ◽  
Vol 42 ◽  
Author(s):  
Emily F. Wissel ◽  
Leigh K. Smith

Abstract The target article suggests inter-individual variability is a weakness of microbiota-gut-brain (MGB) research, but we discuss why it is actually a strength. We comment on how accounting for individual differences can help researchers systematically understand the observed variance in microbiota composition, interpret null findings, and potentially improve the efficacy of therapeutic treatments in future clinical microbiome research.


2021 ◽  
Vol 42 (2) ◽  
pp. 417-446
Author(s):  
Hasibe Kahraman ◽  
Bilal Kırkıcı

AbstractResearch into nonnative (L2) morphological processing has produced largely conflicting findings. To contribute to the discussions surrounding the contradictory findings in the literature, we examined L2 morphological priming effects along with a transposed-letter (TL) methodology. Critically, we also explored the potential effects of individual differences in the reading networks of L2 speakers using a test battery of reading proficiency. A masked primed lexical decision experiment was carried out in which the same target (e.g., ALLOW) was preceded by a morphological prime (allowable), a TL-within prime (allwoable), an substituted letter (SL)-within prime (allveable), a TL-across prime (alloawble), an SL-across prime (alloimble), or an unrelated prime (believable). The average data yielded morphological priming but no significant TL priming. However, the results of an exploratory analysis of the potential effects of individual differences suggested that individual variability mediated the group-level priming patterns in L2 speakers. TL-within and TL-across priming effects were obtained only when the performance of participants on nonword reading was considered, while the magnitude of the morphological priming effects diminished as the knowledge of vocabulary expanded. The results highlight the importance of considering individual differences while testing L2 populations.


2011 ◽  
Vol 23 (12) ◽  
pp. 3903-3913 ◽  
Author(s):  
Tobias Egner

Conflict adaptation—a conflict-triggered improvement in the resolution of conflicting stimulus or response representations—has become a widely used probe of cognitive control processes in both healthy and clinical populations. Previous fMRI studies have localized activation foci associated with conflict resolution to dorsolateral PFC (dlPFC). The traditional group analysis approach employed in these studies highlights regions that are, on average, activated during conflict resolution, but does not necessarily reveal areas mediating individual differences in conflict resolution, because between-subject variance is treated as noise. Here, we employed a complementary approach to elucidate the neural bases of variability in the proficiency of conflict-driven cognitive control. We analyzed two independent fMRI data sets of face–word Stroop tasks by using individual variability in the behavioral expression of conflict adaptation as the metric against which brain activation was regressed while controlling for individual differences in mean RT and Stroop interference. Across the two experiments, a replicable neural substrate of individual variation in conflict adaptation was found in ventrolateral PFC (vlPFC), specifically, in the right inferior frontal gyrus, pars orbitalis (BA 47). Unbiased regression estimates showed that variability in activity in this region accounted for ∼40% of the variance in behavioral expression of conflict adaptation across subjects, thus documenting a heretofore unsuspected key role for vlPFC in mediating conflict-driven adjustments in cognitive control. We speculate that vlPFC plays a primary role in conflict control that is supplemented by dlPFC recruitment under conditions of suboptimal performance.


2017 ◽  
Vol 29 (1) ◽  
pp. 183-202 ◽  
Author(s):  
Yvonne Y. Chen ◽  
Jeremy B. Caplan

During study trials of a recognition memory task, alpha (∼10 Hz) oscillations decrease, and concurrently, theta (4–8 Hz) oscillations increase when later memory is successful versus unsuccessful (subsequent memory effect). Likewise, at test, reduced alpha and increased theta activity are associated with successful memory (retrieval success effect). Here we take an individual-differences approach to test three hypotheses about theta and alpha oscillations in verbal, old/new recognition, measuring the difference in oscillations between hit trials and miss trials. First, we test the hypothesis that theta and alpha oscillations have a moderately mutually exclusive relationship; but no support for this hypothesis was found. Second, we test the hypothesis that theta oscillations explain not only memory effects within participants, but also individual differences. Supporting this prediction, durations of theta (but not alpha) oscillations at study and at test correlated significantly with d′ across participants. Third, we test the hypothesis that theta and alpha oscillations reflect familiarity and recollection processes by comparing oscillation measures to ERPs that are implicated in familiarity and recollection. The alpha-oscillation effects correlated with some ERP measures, but inversely, suggesting that the actions of alpha oscillations on memory processes are distinct from the roles of familiarity- and recollection-linked ERP signals. The theta-oscillation measures, despite differentiating hits from misses, did not correlate with any ERP measure; thus, theta oscillations may reflect elaborative processes not tapped by recollection-related ERPs. Our findings are consistent with alpha oscillations reflecting visual inattention, which can modulate memory, and with theta oscillations supporting recognition memory in ways that complement the most commonly studied ERPs.


1992 ◽  
Vol 160 (S15) ◽  
pp. 36-43 ◽  
Author(s):  
Hymie Anisman ◽  
Robert M. Zacharko

Stressors induce behavioural disturbances and neurochemical changes in animals, some of which are reminiscent of the symptoms and presumed neurochemical concomitants of depression in humans. Just as in humans, where considerable inter-individual variability is evident in the symptom profile of depression, there is marked inter-individual and inter-strain variability in the behavioural effects of stressors in animals. It is proposed that stressors induce adaptive neurochemical changes, failure of which may engender behavioural disturbances. Variability in the symptoms of depression and in the efficacy of its pharmacological treatment may reflect the biochemical heterogeneity of the illness. Inter-individual differences in vulnerability to stressor-provoked neurochemical changes may contribute to the behavioural profiles observed.


2021 ◽  
Vol 8 (3) ◽  
pp. 201558
Author(s):  
Julia D. Kozhevnikova ◽  
Ilya A. Volodin ◽  
Alexandra S. Zaytseva ◽  
Olga G. Ilchenko ◽  
Elena V. Volodina

Among Gerbillinae rodents, ultrasonic calls of adults of small-sized species are typically higher frequency than those of adults of large-sized species. This study investigates whether a similar relationship can be found in pups of six gerbil species ( Dipodillus campestris , Gerbillus perpallidus , Meriones unguiculatus , Meriones vinogradovi , Sekeetamys calurus and Pachyuromys duprasi ). We compared the average values of acoustic variables (duration, fundamental and peak frequency) of ultrasonic calls (20 calls per pup, 1200 in total) recorded from 6- to 10-day-old pups (10 pups per species, 60 in total) isolated for 2 min at 22°C and then weighed and measured for body variables. The longest calls (56 ± 33 ms) were found in the largest species, and the highest frequency calls (74.8 ± 5.59 kHz) were found in the smallest species. However, across species, call duration (ranging from 56 to 159 ms among species) did not display a significant relationship with pup body size; and, among frequency variables, only the minimum fundamental frequency depended on pup body size. Discriminant analysis assigned 100% of calls to the correct species. The effect of species identity on the acoustics was stronger than the effect of body size. We discuss these results with the hypotheses of acoustic adaptation, social complexity, hearing ranges and phylogeny.


Author(s):  
C. Terlouw ◽  
A.B. Lawrence ◽  
A.W. Illius

Animals show considerable individual variation in many behaviour patterns such as feeding and mating behaviour. Often, this individual variability is ignored in favour of a more general description of the population. However, this may mask important information regarding the causes and functions of this individual variability. Behavioural work on other species has suggested that individuals tend to respond actively or passively to environmental challenge. It is of interest to know if a similar dimension of responsiveness exists in pigs as it may serve, amongst other things, to explain the considerable individual variability in pigs responses to putitive stresses such as tethered housing. This paper describes a series of tests made of behavioural responsiveness in pigs to assess the extent of consistent variability in individuals responses to a wide variety of environmental challenges.The subjects were two groups [Group A and B: n = 26 and 36 respectively) of modern hybrid non-pregnant gilts [Cotswold Pig Development Company Ltd, UK). Initially, the gilts were subjected to a number of tests of behavioural responsiveness at the Cotswold unit.


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