Increased Response Latencies Research Articles

Noise-induced hearing loss in zebrafish: investigating structural and functional inner ear damage and recovery

Exposure to continuous moderate noise levels is known to impair the auditory system leading to Noise-Induced Hearing Loss (NIHL) in animals including humans. The mechanism underlying noise-dependent auditory Temporary Threshold Shifts (TTS) is not fully understood. In fact, only limited information is available on vertebrates such as fishes, which share homologous inner ear structures to mammals and have the ability to regenerate hair cells. The zebrafish Danio rerio is a well-established model in hearing research providing an unmatched opportunity to investigate the molecular and physiological mechanisms of NIHL at the sensory receptor level. Here we investigated for the first time the effects of noise exposure on TTS and functional recovery in zebrafish, as well as the associated morphological damage and regeneration of the inner ear saccular hair cells.Adult specimens were exposed for 24h to white noise at various amplitudes (130, 140 and 150 dB re. 1 μPa) and their auditory sensitivity was subsequently measured with the Auditory Evoked Potential (AEP) recording technique. Sensory recovery was tested at different times post-treatment (after 3, 7 and 14 days) and compared to individuals kept under quiet lab conditions. Results revealed noise level-dependent TTS up to 33 dB and increase in response latency. Recovery of hearing function occurred within 7 days for fish exposed to 130 and 140 dB noise levels, while fish subject to 150 dB only returned to baseline thresholds after 14 days. Hearing impairment was accompanied by significant loss of hair cells only at the highest noise treatment. Full regeneration of the sensory tissue (number of hair cell receptors) occurred within 7 days, which was prior to functional recovery.We provide first baseline data of NIHL in zebrafish and validate this species as an effective vertebrate model to investigate the impact of noise exposure on the structure and function of the adult inner ear and its recovery process.

Antipyretic, anti-inflammatory and analgesic activities of Periplaneta americana extract and underlying mechanisms

Periplaneta americana is a common traditional Chinese medicinal material which has been used to treat arthritis, fever, aches, pains, and inflammation of the extremities for several hundred years. However, little scientific data exists in literature to support its use. The purpose of this study was to evaluate the antipyretic, anti-inflammatory and analgesic activities of Periplaneta americana extract (PAE) and explore its underlying mechanism. The antipyretic, anti-inflammatory and analgesic activities were evaluated by LPS-induced fever, carrageenan-induced paw edema, abdominal writhing, hot plate and formalin tests, respectively. The mechanism of action was explored by antioxidant activity analysis, inflammatory cytokines expression and febrile mediator measurement, and pathway activation analysis. The results from UHPLC-HRMS indicated that the extract was found to contain dopamine, coumarin, dipeptide, vitamin, organic acid, amino acid and its metabolites, and other organic compounds. PAE showed in a dose-dependent manner antioxidant activity and reduced the protein production and mRNA expression of NO, IL-1β, IL-6, and TNF-α in RAW 264.7 cells in vitro. Moreover, PAE significantly and dose-dependently inhibited the writhing responses and licking time in formalin tests, increased response latency in the hot plate test, reduced carrageenan-induced paw edema and inflammation in mice, decreased LPS-induced rT increase in rats. Furthermore, PAE treatment markedly inhibited the increase in the levels of NO, IL-6, IL-1β, TNF-α, PGE2 and cAMP in plasma of fevered rat, greatly suppressed the activation of inflammatory response pathway and the change of MDA and GSH concentration, MPO and SOD activity as well as FRAP capacity in paw induced by carrageenan injection. In conclusion, the findings suggested that PAE produced potential antinociceptive, anti-inflammatory and antipyretic effects by reducing production of endogenous inflammatory mediators and blocking the MAPK/NF-κB signaling pathway which support the claim for its traditional use in the treatment of various diseases.

Assessing the motivational effects of ethanol in mice using a discrete-trial current-intensity intracranial self-stimulation procedure

BackgroundAlcohol (ethanol) produces both rewarding and aversive effects, and sensitivity to these effects is associated with risk for an alcohol use disorder (AUD). Measurement of these motivational effects in animal models is an important but challenging aspect of preclinical research into the neurobiology of AUD. Here, we evaluated whether a discrete-trial current-intensity intracranial self-stimulation (ICSS) procedure can be used to assess both reward-enhancing and aversive responses to ethanol in mice. MethodsMale and female C57BL/6J mice were surgically implanted with bipolar stimulating electrodes targeting the medial forebrain bundle and trained on a discrete-trial current-intensity ICSS procedure. Mice were tested for changes in response thresholds after various doses of ethanol (0.5 g/kg-1.75 g/kg; n = 5–7 per dose), using a Latin square design. ResultsA 1 g/kg dose of ethanol produced a significant reward-enhancement (i.e., lowered response thresholds), whereas a 1.75 g/kg dose produced an aversive effect (elevated response thresholds). Ethanol doses from 1 to 1.75 g/kg increased response latencies as compared to saline treatment. ConclusionsThe discrete-trial current-intensity ICSS procedure is an effective assay for measuring both reward-enhancing responses to ethanol as well as aversive responses in the same animal. This should prove to be a useful tool for assessing the effects of experimental manipulations on the motivational effects of ethanol in mice.

Effect of within-session breaks in play on responsible gambling behaviour during sustained monetary losses

Rapid, continuous gambling formats are associated with higher risks for gambling-related harm in terms of excessive monetary and time expenditure. The current study investigated the effect on gambling response latency and persistence, of a new form of within-game intervention that required players to actively engage in response inhibition via monitoring for stop signals. Seventy-four experienced electronic gaming machine gamblers, with a mean age of 35.28 years, were recruited to participate in a rapid, continuous gambling task where real money could be won and lost. Participants were randomly allocated to either the control condition where no intervention was presented, or either a condition with a passive three minute break in play or a condition with a three minute intervention that required participants to engage in response inhibition. Although there was no main effect for experimental condition on gambling persistence, both interventions were effective in elevating response latency during a period of sustained losses. It was concluded that within-game interventions that create an enforced break in play are effective in increasing response latency between bets during periods of sustained losses. Furthermore, within-game interventions that require active involvement appear to be more effective in increasing response latency than standard, passive breaks in play.

Cue utilization differentiates resource allocation during sustained attention simulated rail control tasks.

This study was designed to examine whether cue utilization differentiates performance and resource allocation during simulated rail control tasks that contain implicit patterns of train movement. Two experiments were conducted, the first of which involved the completion of a 30-min rail control simulation that required participants to reroute trains either infrequently (monitoring task) or periodically (process control task). In the monitoring condition, participants with lower cue utilization recorded a greater increase in response latency over time. However, in the process control condition, cue utilization failed to differentiate performance. In the second experiment, the duration of the rail control task was increased, and measures of participant fixation rates and cerebral blood flow were taken. Participants with higher cue utilization demonstrated greater decreases in fixation rates, smaller changes in cerebral oxygenation in the prefrontal cortex, and smaller increases in response latencies, compared with participants with lower cue utilization. The results of the study provide support for the assertion that a relatively greater capacity for cue utilization is associated with the allocation of fewer cognitive resources during sustained attention tasks that embody an implicit pattern of activity. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The effects of mitragynine and morphine on schedule-controlled responding and antinociception in rats.

Mitragyna speciosa (kratom) may hold promise as both an analgesic and treatment for opioid use disorder. Mitragynine, its primary alkaloid constituent, is an opioid receptor ligand. However, the extent to which the in vivo effects of mitragynine are mediated by opioid receptors, or whether mitragynine interacts with other opioid agonists, is not fully established. The effects of mitragynine and the prototypical opioid agonist morphine were compared for their capacity to decrease operant responding for food delivery, and to increase response latency to a thermal stimulus. Male and female Sprague-Dawley rats responded under a multiple cycle fixed ratio 10 schedule of food delivery and were tested on a hot plate (52°C) immediately after each cycle. Morphine and mitragynine were administered alone, in combination with each other, and in combination with the opioid antagonist naltrexone. Morphine and mitragynine dose-dependently decreased schedule-controlled responding; the ED50 values were 7.3 and 31.5mg/kg, respectively. Both drugs increased thermal antinociception; the ED50 value for morphine was 18.3. Further, doses of naltrexone that antagonized morphine did not antagonize mitragynine. Mitragynine (17.8mg/kg) did not alter the rate-decreasing or antinociceptive effects of morphine. The antinociceptive effects of mitragynine and morphine occur at doses larger than those that disrupt learned behavior. Opioid receptors do not appear to mediate the disruptive effects of mitragynine on learned behavior. Mitragynine had lesser antinociceptive effects than morphine, and these did not appear to be mediated by opioid receptors. The pharmacology of mitragynine includes a substantial non-opioid mechanism.

The Effect of Cerebellar tDCS on Sequential Motor Response Selection

Transcranial direct current stimulation (tDCS) transiently alters cortical excitability and synaptic plasticity. So far, few studies have investigated the behavioral effects of applying tDCS to the cerebellum. Given the cerebellum’s inhibitory effects on cortical motor areas as well as its role in fine motor control and motor coordination, we investigated whether cerebellar tDCS can modulate response selection processes and motor sequence learning. Seventy-two participants received either cerebellar anodal (excitatory), cathodal (inhibitory), or sham (placebo) tDCS while performing a serial reaction time task (SRTT). To compare acute and long-term effects of stimulation on behavioral performance, participants came back for follow-up testing at 24 h after stimulation. Results indicated no group differences in performance prior to tDCS. During stimulation, tDCS did not affect sequence-specific learning, but anodal as compared to cathodal and sham stimulations did modulate response selection processes. Specifically, anodal tDCS increased response latencies independent of whether a trained or transfer sequence was being performed, although this effect became smaller throughout training. At the 24-h follow-up, the group that previously received anodal tDCS again demonstrated increased response latencies, but only when the previously trained sequence and a transfer sequence had to be performed in the same experimental block. This increased behavioral interference tentatively points to a detrimental effect of anodal cerebellar tDCS on sequence consolidation/retention. These results are consistent with the notion that the cerebellum exerts an inhibitory effect on cortical motor areas, which can impair sequential response selection when this inhibition is strengthened by tDCS.

Intrauterine growth restriction and neonatal hypoxic ischemic brain injury causes sex-specific long-term neurobehavioral abnormalities in rats.

There is a lack of knowledge of factors preventing an adequate response to moderate hypothermia after hypoxic ischemic (HI) brain injury. We hypothesized that growth restriction from reduced intrauterine perfusion would predispose neonatal rats to have a worse outcome with HI brain injury. IUGR was induced by placental insufficiency in dams at 14 days of gestation. HI was induced at postnatal day (P) 10 by permanent right carotid artery ligation followed by 90 min of hypoxia (8% oxygen). Tests for early brain injury and neurobehavioral outcomes were subsequently done. All statistical analysis was done using Two-way ANOVA; post hoc Holm-Sidak test. HI in control and IUGR groups decreased the success rate of the contralateral vibrissa-elicited forelimb test, increased response latency in movement initiation test and increased the time to finish elevated beam walk test at P40 and P60. IUGR augmented HI-induced abnormality in vibrissa-elicited forelimb test at P40 but showed higher success rate when compared to HI only group at P60. IUGR's negative effect on HI-induced changes on the elevated beam walk test was sex-specific and exaggerated in P60 males. Increased TUNEL positive cells in the cortex were noted at 72 h after in HI in control but not in IUGR groups. In conclusion, the consequences of IUGR on subsequent neonatal HI varied based on age, sex and outcomes examined, and overall, male sex and IUGR had worse effects on the long-term neurobehavioral outcomes following HI.

Reversing Time and Size: Mutual Entailment of Nonarbitrary Temporal and Magnitude Relational Responding

Responding to temporal relational statements that include the original events (e.g., A. .. B) in a reversed order (e.g., “B after A”) is less accurate and more time-consuming than responding to such statements when they retain the original order of presentation (e.g., “A before B”). The current study assessed whether this effect was limited to temporal relational responding by estimating the effect of reversal on magnitude statements (e.g., “B bigger than A”) as well as temporal statements. Participants (N = 40) completed temporal and magnitude relational judgement tasks in blocks consisting of a training phase and a testing phase. The order of relational tasks was counterbalanced across participants; participants learned the second type of relational task faster than the first. During testing, reversal of the order of stimuli in both temporal and magnitude relations reduced accuracy and increased response latencies suggesting that the reversal effect was not limited to temporal relations. The findings support the position that a general relational effect, such as mutual entailment, may underlie the increased difficulty of reversed temporal relational statements.

The efficacy of microemulsion-based delivery to improve vitamin E properties: evaluation of the antinociceptive, antioxidant, antidepressant- and anxiolytic-like activities in mice.

A microemulsion-based delivery system was designed to improve vitamin E (VE) properties, and its antinociceptive, antioxidant, antidepressant- and anxiolytic-like activities in mice were evaluated. Male Swiss mice received, by intragastric route, canola oil (20ml/kg), blank microemulsion (B-ME) (20ml/kg), VE free (VE-F) (200mg/kg) or VE microemulsion (VE-ME) (200mg/kg). In acute treatment, a single dose of treatments was administrated and 30min after behavioural tests were performed. In the subchronic treatment, mice received such treatments, once a day, for 8days. On the eighth day, behavioural tests were performed. In the subchronic treatment, VE-ME increased entries and spent time in the open arms in the elevated plus-maze test and decreased the immobility time in the tail suspension test, but no change was found after acute treatment. Acute and subchronic treatments with VE-ME increased response latency to thermal stimulus in the hot-plate test. VE-ME decreased the thiobarbituric acid reactive species levels in the acute and subchronic protocols. Additionally, in subchronic treatment, VE-ME increased renal catalase activity, but VE-F reduced its activity. Vitamin E-microemulsions showed antioxidant, antinociceptive, antidepressant- and anxiolytic-like actions; thus, ME-based delivery improved pharmacological properties of VE.

Cue Utilization Predicts Resource Allocation during Rail Control Simulations: A NIRS Study

This study was designed to examine whether cue utilization differentiates performance and resource allocation during simulated monitoring and process control tasks. The experiment involved the completion of a 45-minute rail control simulation that required participants to re-route trains either infrequently (monitoring task) or periodically (process control task). Implicit patterns of train movement were incorporated into the rail control task. Measures of participants’ response latency, fixation rates and cerebral blood flow were taken. Participants with higher cue utilization demonstrated greater decreases in fixation rates, smaller changes in cerebral oxygenation in the prefrontal cortex, and smaller increases in response latencies. The results provide support for the assertion that a relatively greater capacity for cue utilization is associated with the allocation of fewer cognitive resources during sustained attention tasks.

Humans and Algorithms for Facial Recognition: The Effects of Candidate List Length and Experience on Performance

These experiments investigated how the candidate list displayed to facial reviewers affects their performance in a one-to-many unfamiliar face matching task. Automated facial recognition systems present the results of a database search and require selection of an image that matches the target. Few studies investigate how humans in combination with facial recognition algorithms perform within different operational contexts. These experiments investigated how the candidate list displayed to facial reviewers affects their performance in a one-to-many unfamiliar face matching task. We tested candidate list length with inexperienced (Experiment 1) and experienced (Experiment 2) facial reviewers. Candidate list length had a large impact on performance, varying with the operational context. However, response-time analyses show that the accurate responses were resolved quickly, with an error-prone guess process implemented after failed search. Long candidate lists (100 images) produced more false alarms, fewer hits, lower decision confidence, and increased response latencies among both inexperienced and experienced facial reviewers.

Orthographic effects in second-language spoken-word recognition.

Evidence from both alphabetic and nonalphabetic languages has suggested the role of orthography in the processing of spoken words in individuals' native language (L1). Less evidence has existed for such effects in nonnative (L2) spoken-word processing. Whereas in L1 orthographic representations are learned only after phonological representations have long been established, in L2 the sound and spelling of words are often learned in conjunction; this might predict stronger orthographic effects in L2 than in L1 spoken processing. On the other hand, lexical codes are typically less integrated and stable in L2 than in L1, which might entail less pronounced orthographic effects. To explore this issue, Tibetan Chinese bilinguals judged whether Chinese spoken words presented in pairs were related in meaning. Some of the unrelated word pairs were orthographically related, and critically, this orthographic overlap induced a significant increase in response latencies. Compared to previous results from L1 listeners with the identical procedure, the orthographic effect for L2 listeners was more pronounced. These findings indicate that orthographic information is involuntarily accessed in native and nonnative spoken-word recognition alike and that it may play a more important role in the latter compared to the former. (PsycINFO Database Record

Working Memory Updating: Load and Binding

ABSTRACTIn the present study, we aimed to examine how specific objects are updated in working memory. We compared conditions in which contents or content-context bindings from working memory were both encoded and updated (Experiment 1). In addition, for bindings, we manipulated the memory load (i.e., number of contents) to maintain during updating. Results indicated that memory load did not specifically affect the process; rather, the content-context binding (vs. single contents) was critical in determining the increase in response latencies. Results were replicated even in Experiment 2, in which we manipulated the spatial locations of the to-be-recognized probes. Results showed evidence of a potential dissociation between updating of memory contents-only and content-context bindings. In addition, memory load and spatial coherence between phases and probe recognition did not interact with updating performance. Overall, results were taken as a contribution toward mapping the complex nature of the updating mechanism.

Cooperative cortical network for categorical processing of Chinese lexical tone

In tonal languages such as Chinese, lexical tone with varying pitch contours serves as a key feature to provide contrast in word meaning. Similar to phoneme processing, behavioral studies have suggested that Chinese tone is categorically perceived. However, its underlying neural mechanism remains poorly understood. By conducting cortical surface recordings in surgical patients, we revealed a cooperative cortical network along with its dynamics responsible for this categorical perception. Based on an oddball paradigm, we found amplified neural dissimilarity between cross-category tone pairs, rather than between within-category tone pairs, over cortical sites covering both the ventral and dorsal streams of speech processing. The bilateral superior temporal gyrus (STG) and the middle temporal gyrus (MTG) exhibited increased response latencies and enlarged neural dissimilarity, suggesting a ventral hierarchy that gradually differentiates the acoustic features of lexical tones. In addition, the bilateral motor cortices were also found to be involved in categorical processing, interacting with both the STG and the MTG and exhibiting a response latency in between. Moreover, the motor cortex received enhanced Granger causal influence from the semantic hub, the anterior temporal lobe, in the right hemisphere. These unique data suggest that there exists a distributed cooperative cortical network supporting the categorical processing of lexical tone in tonal language speakers, not only encompassing a bilateral temporal hierarchy that is shared by categorical processing of phonemes but also involving intensive speech-motor interactions over the right hemisphere, which might be the unique machinery responsible for the reliable discrimination of tone identities.

Understanding and Leveraging the Impact of Response Latency on User Behaviour in Web Search

The interplay between the response latency of web search systems and users’ search experience has only recently started to attract research attention, despite the important implications of response latency on monetisation of such systems. In this work, we carry out two complementary studies to investigate the impact of response latency on users’ searching behaviour in web search engines. We first conduct a controlled user study to investigate the sensitivity of users to increasing delays in response latency. This study shows that the users of a fast search system are more sensitive to delays than the users of a slow search system. Moreover, the study finds that users are more likely to notice the response latency delays beyond a certain latency threshold, their search experience potentially being affected. We then analyse a large number of search queries obtained from Yahoo Web Search to investigate the impact of response latency on users’ click behaviour. This analysis demonstrates the significant change in click behaviour as the response latency increases. We also find that certain user, context, and query attributes play a role in the way increasing response latency affects the click behaviour. To demonstrate a possible use case for our findings, we devise a machine-learning framework that leverages the latency impact, together with other features, to predict whether a user will issue any clicks on web search results. As a further extension of this use case, we investigate whether this machine-learning framework can be exploited to help search engines reduce their energy consumption during query processing.

Learning and Judgment Can Be Affected by Predisposed Fearfulness in Laying Hens.

High fearfulness could disrupt learning and likely affects judgment in animals, especially when it is part of an animals’ personality, i.e., trait anxiety. Here, we tested whether high fearfulness affects discrimination learning and judgment bias (JB) in laying hens. Based on the response to an open field at 5 weeks of age, birds were categorized as fearful (FC) by showing no walking or vocalizing or non-fearful (NFC) by showing walking and vocalizing. At adult age, birds (n = 24) were trained in a go–go task to discriminate two cues (white or black) with a small or large reward. Birds that reached training criteria were exposed to three unrewarded ambiguous cues (25, 50, and 75% black) to assess JB. Task acquisition took longer for FC birds than for NFC birds, due to a left side bias, and more sessions were needed to unlearn this side bias. Changes in trial setup increased response latencies for FC birds but not for NFC birds. A larger number of FC birds than NFC birds chose optimistically in the last ambiguous trial (25% black). FC birds had a longer latency to choose in the ambiguous trial (75% black) compared to NFC birds. Prior choice in ambiguous trials and a preceding large or small trial affected latencies and choices for both types of birds. Our study showed that fearfulness was associated with differences in discrimination learning ability and JB. It appeared that FC birds used a rigid response strategy during early learning phases by choosing a specific side repeatedly irrespective of success. FC birds were more affected by changes in the setup of the trials in comparison to NFC birds. We speculate that FC birds are more sensitive to changes in environmental cues and reward expectancy. These factors could explain how high fearfulness affects learning.

Inflammatory Pain Reduces C Fiber Activity-Dependent Slowing in a Sex-Dependent Manner, Amplifying Nociceptive Input to the Spinal Cord.

C fibers display activity-dependent slowing (ADS), whereby repetitive stimulation (≥1 Hz) results in a progressive slowing of action potential conduction velocity, which manifests as a progressive increase in response latency. However, the impact of ADS on spinal pain processing has not been explored, nor whether ADS is altered in inflammatory pain conditions. To investigate, compound action potentials were made, from dorsal roots isolated from rats with or without complete Freund's adjuvant (CFA) hindpaw inflammation, in response to electrical stimulus trains. CFA inflammation significantly reduced C fiber ADS at 1 and 2 Hz stimulation rates. Whole-cell patch-clamp recordings in the spinal cord slice preparation with attached dorsal roots also demonstrated that CFA inflammation reduced ADS in the monosynaptic C fiber input to lamina I neurokinin 1 receptor-expressing neurons (1–10 Hz stimulus trains) without altering the incidence of synaptic response failures. When analyzed by sex, it was revealed that females display a more pronounced ADS that is reduced by CFA inflammation to a level comparable with males. Cumulative ventral root potentials evoked by long and short dorsal root stimulation lengths, to maximize and minimize the impact of ADS, respectively, demonstrated that reducing ADS facilitates spinal summation, and this was also sex dependent. This finding correlated with the behavioral observation of increased noxious thermal thresholds and enhanced inflammatory thermal hypersensitivity in females. We propose that sex/inflammation-dependent regulation of C fiber ADS can, by controlling the temporal relay of nociceptive inputs, influence the spinal summation of nociceptive signals contributing to sex/inflammation-dependent differences in pain sensitivity.SIGNIFICANCE STATEMENT The intensity of a noxious stimulus is encoded by the frequency of action potentials relayed by nociceptive C fibers to the spinal cord. C fibers conduct successive action potentials at progressively slower speeds, but the impact of this activity-dependent slowing (ADS) is unknown. Here we demonstrate that ADS is more prevalent in females than males and is reduced in an inflammatory pain model in females only. We also demonstrate a progressive delay of C fiber monosynaptic transmission to the spinal cord that is similarly sex and inflammation dependent. Experimentally manipulating ADS strongly influences spinal summation consistent with sex differences in behavioral pain thresholds. This suggests that ADS provides a peripheral mechanism that can regulate spinal nociceptive processing and pain sensation.

Selective Attention, Schizotypy and Age: A Meta-Analysis

The current study was a meta-analysis that examined differences in selective attention as a function of age, schizotypy and gender. The particular effect examined, negative priming (Tipper, 1985), was the increased response latency for previously ignored information. Results demonstrated that age, schizotypy, and gender all moderated the negative priming effect. The effects of age were the clearest: younger adults showed a stronger negative priming than older adults. The specific effects of schizotypy and gender were less clear. However, results suggested the following: males show stronger negative priming than women, and adults scoring low on a schizotypy show stronger effects than those scoring high.

Prefrontal cortex stimulation does not affect emotional bias, but may slow emotion identification.

Transcranial direct current stimulation (tDCS) has recently garnered attention as a putative depression treatment. However, the cognitive mechanisms by which it exerts an antidepressant effect are unclear: tDCS may directly alter ‘hot’ emotional processing biases, or alleviate depression through changes in ‘cold’ (non-emotional) cognitive function. Here, 75 healthy participants performed a facial emotion identification task during 20 minutes of anodal or sham tDCS over the left dorsolateral prefrontal cortex (DLPFC) in a double-blind, within-subject crossover design. A subset of 31 participants additionally completed a task measuring attentional distraction during stimulation. Compared to sham stimulation, anodal tDCS of the left DLPFC resulted in an increase in response latency across all emotional conditions. Bayesian analysis showed definitively that tDCS exerted no emotion-dependent effect on behaviour. Thus, we demonstrate that anodal tDCS produces a general, rather than an emotion-specific, effect. We also report a preliminary finding in the subset of participants who completed the distractibility task: increased distractibility during active stimulation correlated significantly with the degree to which tDCS slowed emotion identification. Our results provide insight into the possible mechanisms by which DLPFC tDCS may treat symptoms of depression, suggesting that it may not alter emotional biases, but instead may affect ‘cold’ cognitive processes.