90 research outputs found
How we Can change your mind: Anodal tDCS to Fp3 alters human stimulus representation and learning.
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The aim of the current work is to advance our understanding of both the mechanisms controlling perceptual learning and the face inversion effect. In the three double blind experiments reported here (total N=144) we have shown that anodal tDCS stimulation (10 mins at 1.5 mA) delivered over the left DLPFC at Fp3 affects perceptual learning and drastically reduces the, usually robust, face inversion effect. In Experiment 1, we found a significantly reduced inversion effect in the anodal group compared to that in the sham group. Experiment 2 replicated the pattern of results found in Experiment 1. In both experiments recognition performance for upright faces in the anodal group was significantly impaired compared to that in the sham group. Finally, using an active control in Experiment 3 (same behavioural task but different tDCS targeted brain area) we showed that the same Fp3 anodal tDCS stimulation effect is not obtained when a different brain area is targeted.This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 743702 awarded to Ciro Civile. This project has also received funding from the Economic and Social Research Council (ESRC) New Investigator Grant (Ref. ES/R005532) awarded to Ciro Civile (PI) and I.P.L. McLaren (Co-I)
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Pre-exposure and learning in young children: Evidence of latent inhibition?
Previous research by Kaniel & Lubow in 1986 found that youngchildren (aged 4-5 years) exhibited poorer learning (latentinhibition) to pre-exposed stimuli than older children (aged 7-10years). The aim of our research was to develop a computer-based,child-friendly study that would replicate the work of Kaniel &Lubow. Sixty-three children took part in our experiment. Thisconsisted of a pre-exposure/study phase in which participants wereasked to press computer keys in response to clipart pictures ofanimals and dinosaurs. Each animal or dinosaur picture waspreceded by one of two âwarning signalsâ which acted as the pre-exposed stimuli (to which no response was required). In the testphase that followed, the participants had to either press thespacebar or withhold their response to each pre-exposed stimulusand two novel stimuli. They learnt which response was correct bytrial and error using the feedback provided. The accuracy andreaction time of the responses during the test phase were analysedand indicated that the youngest children showed significantlylower mean accuracy and longer mean response times to the pre-exposed stimuli than to stimuli they had not been pre-exposed to.In contrast, the older children showed no significant differences intheir responses to pre-exposed and novel stimuli. These results areconsistent with those found by Kaniel & Lubow and could be takenas evidence for latent inhibition in young children. Further studiesare proposed in which variations in pre-exposure procedure areused to rule out explanations based on response inhibition ornegative priming
The Role of Experience-based Perceptual Learning in the Face Inversion Effect
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Perceptual learning of the type we consider here is a consequence of experience with a class of
stimuli. It amounts to an enhanced ability to discriminate between stimuli. We argue that it
contributes to the ability to distinguish between faces and recognize individuals, and in particular
contributes to the face inversion effect (better recognition performance for upright vs inverted
faces). Previously, we have shown that experience with a prototype defined category of
checkerboards leads to perceptual learning, that this produces an inversion effect, and that this
effect can be disrupted by Anodal tDCS to Fp3 during pre-exposure. If we can demonstrate that
the same tDCS manipulation also disrupts the inversion effect for faces, then this will strengthen
the claim that perceptual learning contributes to that effect. The important question, then, is
whether this tDCS procedure would significantly reduce the inversion effect for faces; stimuli
that we have lifelong expertise with and for which perceptual learning has already occurred.
Consequently, in the experiment reported here we investigated the effects of anodal tDCS at Fp3
during an old/new recognition task for upright and inverted faces. Our results show that
stimulation significantly reduced the face inversion effect compared to controls. The effect was
one of reducing recognition performance for upright faces. This result is the first to show that
tDCS affects perceptual learning that has already occurred, disrupting individualsâ ability to
recognize upright faces. It provides further support for our account of perceptual learning and its
role as a key factor in face recognition
Transcranial Direct Current Stimulation (tDCS) and the Face Inversion Effect: Anodal stimulation at Fp3 reduces recognition for upright faces
This is the final version of the article. Available from the publisher via the link in this record.Perceptual learning is a key perceptual skill that people possess,
in particular, it contributes to their ability to distinguish between
faces thus recognize individuals. Recently, we showed that anodal
transcranial Direct Current Stimulation (tDCS) at Fp3 abolishes
the inversion effect (that would otherwise exist) for familiar
checkerboards created from a prototype. Because of the close
analogy between the inversion effect obtained with checkerboards,
which we use as a marker for perceptual learning, and the
traditional face inversion effect (upright faces recognized better
than inverted ones), we investigated the effects of anodal tDCS at
Fp3 during an old/new recognition task for upright and inverted
faces. Results showed that stimulation significantly reduced the
face inversion effect compared to controls. The effect was
strongest in reducing recognition performance to upright faces.
This result supports our account of perceptual learning and its role
as a key factor in face recognitio
Directional cue and landmark configurations: The effect of rotating one set of landmarks relative to another
This is the author accepted manuscript. The final version is available from the American Psychological Association via the DOI in this recordIn this article we addressed the question whether rats can use distal landmarks as directional cues that are used in combination with other proximal landmark configurations. The animals were trained with an A, B, C, and D landmark configuration in the Morris pool, where B and C are the near (to platform) landmarks and A and D the far ones. We also added another more distal "directional" cue Z (a white strip attached to the black curtain surrounding the pool). Experiment 1 shows a robust detrimental effect on the time spent by the rats swimming in the platform quadrant when the location of all landmarks was "Inverted" (rotated by 180 degrees) with respect to Z. A similar detrimental effect was found when, after the inversion manipulation, the locations of the near and far landmarks were "Flipped" (B swapped with C and A with D). Rats in both Inverted and Flipped tests spent more time in the Z quadrant compared to the platform quadrant (BC). Experiment 1b provided evidence distinguishing between alternative explanations of how the directional cue Z acts in combination with the other landmarks. The results from both experiments show that Z operates differently to the standard landmarks. It can function as a beacon in its own right. It can also combine with the other landmarks to produce a high level of search performance, in a way that we hypothesize to be distinct from that described by the configural analysis often applied to multiple landmarks.European Union Horizon 2020Economic and Social Research Council (ESRC
Labelling faces as âAutisticâ reduces the Inversion Effect
This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this recordDoes the belief that a face belongs to an individual with autism affect recognition of that face? To address this question, we used the inversion effect as a marker of face recognition. In Experiment 1, participants completed a recognition task involving upright and inverted faces labelled as either âregularâ or âautisticâ. In reality, the faces presented in both conditions were identical. Results revealed a smaller inversion effect for faces labelled as autistic. Thus, simply labelling a face as âautisticâ disrupts recognition. Experiment 2 showed a larger inversion effect after the provision of humanizing versus dehumanizing information about faces labelled as âautisticâ. We suggest changes in the inversion effect could be used as a measure to study stigma within the context of objectification and dehumanization.S.S.O. is supported by a discovery grant from the Natural
Sciences and Engineering Research council of Canada. C.C. is
supported by the European Unionâs Horizon 2020 research and
innovation programme under the Marie Sklodowska-Curie (grant
agreement No. 743702) and by the Economic and Social Research
Council (ESRC) New Investigator Grant (Ref. ES/R005532)
Switching off perceptual learning: tDCS to left DLPFC eliminates perceptual learning in humans.
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Perceptual learning can be acquired as a result of experience with stimuli that would otherwise be difficult to tell apart, and is often explained in terms of the modulation of feature salience by an error signal based on how well that feature can be predicted by the others that make up the stimulus. In this article we show that anodal transcranial Direct Current Stimulation (tDCS) at Fp3 directly influences this modulation process so as to eliminate and possibly reverse perceptual learning. In 2 experiments, anodal stimulation disrupted perceptual learning (indexed by an inversion effect) compared with sham (Experiment 1) or cathodal (Experiment 2) stimulation. Our findings can be interpreted as showing that anodal tDCS severely reduced or even abolished the modulation of salience based on error, greatly increasing generalization between stimuli. This result supports accounts of perceptual learning based on variations in salience as a consequence of pre-exposure, and opens up the possibility of controlling this phenomenon.IPLM and FV are supported by a grant from the ESRC (ES/J00815X/1), and FV is
supported by a starting grant from the European Research Council (ERC) under the European
Union's Seventh Framework Programme (FP7/2007-2013)/ ERC Grant Agreement No.
312445. CC was supported by an Overseas Scholarship from the International Office at the
University of Exeter and Yixuan Ku by the National Key Fundamental Research (973)
Program (2013CB329501) of China
The effect of scrambling upright and inverted faces on the N170
This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record.The face inversion effect refers to a decrement in performance when we try to recognise
familiar faces turned upside down (inverted), compared to familiar faces presented in their usual
(upright) orientation. Recently, we have demonstrated that the inversion effect can also be found
with checkerboards drawn from prototype-defined categories when the participants have been
trained with these categories, suggesting that factors such as expertise and the relationships
between stimulus features, may be important determinants of this effect. We also demonstrated
that the typical inversion effect on the N170 seen with faces is found with checkerboards,
suggesting that modulation of the N170 is a marker for disruption in the use of configural
information. In the present experiment, we first demonstrate that our scrambling technique
greatly reduces the inversion effect in faces. Following this, we used Event-Related Potentials
(ERPs) recorded while participants performed an Old/New recognition study on normal and
scrambled faces presented in both upright and inverted orientations to investigate the impact of
scrambling on the N170. We obtained the standard robust inversion effect for normal faces: The
N170 was both larger and delayed for normal inverted faces as compared to normal upright
faces, whereas a significantly reduced inversion effect was recorded for scrambled faces. These
results show that the inversion effect on the N170 is greater for normal compared to scrambled
faces, and we interpret the smaller effect for scrambled faces as being due to the reduction in
expertise for those faces consequent on scramblingThis project has received funding from the European Unionâs Horizon 2020 research and
innovation programme under the Marie Sklodowska-Curie grant agreement No 74370
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Using transcranial Direct Current Stimulation (tDCS) to modulate the face inversion effect on the N170 ERP component
This is the final version. Available from the Cognitive Science Society via the link in this recordIn the present study, we combined tDCS and EEG to examine the
electrophysiological responses to the tDCS-induced effects on
the face inversion effect showed in recent studies. A double-blind
procedure with a between-subjects design (n=48) was used with
the subjects, recruited from the student population, being
randomly assigned to either tDCS anodal or sham condition. The
tDCS stimulation was delivered over the DLPFC at Fp3 site for
10 min at an intensity of 1.5mA while subjects engaged in an
old/new recognition task traditionally used to obtain the
inversion effect. The behavioural results generally confirmed
previous findings. Critically, the results from the N170 show an
effect of tDCS. Specifically, the tDCS procedure was able to
modulate the N170 peak component by reducing the inversion
effect on the latencies (i.e. less delay between upright and
inverted faces) and by increasing the inversion effect on the
amplitudes (i.e. larger N170 for inverted vs upright faces). We
interpret the results based on the previous literature in regard to
the inversion effect on the N170 component.European Union Horizon 2020Economic and Social Research Council (ESRC
Editorial: Special Issue on Recent Advances in Perceptual Learning
This is the author accepted manuscript. The final version is available from the American Psychological Association via the DOI in this recor
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