1,720,973 research outputs found
How face perception and visual orienting interact: a comparison between infants and adults
Full text linkThe aim of this dissertation is to investigate the role of face and non-face stimuli in influencing the orienting of visuo-spatial attention, both in infants and adults. Visual orienting of attention and face processing are two theme issues that, separately, have a long research tradition. Less extensive is the literature that has tried to connect the two areas, to verify whether face stimuli, to which we are biased to pay attention even from birth, might bias the allocation of visual attention, when compared with non-face stimuli. Considering that faces in adults are processing by a specific anatomical and functional face system, that becomes increasingly specialized as a consequence of an experience-dependent activity, the purpose of this dissertation is to compare the performance of adult participants and infant participants of different ages. In particular, the hypothesis is that, given a different degree of experience with faces in infancy and adulthood, different will be the degree of influence of this stimuli on orienting of visual attention.
With this consideration in mind, my dissertation begins with three theoretical chapters: Chapter 1 describes the mechanisms of visual orienting and the way to study it in adults; Chapter 2 refers to the development of visual orienting in infancy jointly to the maturation of neural substrates that mediate its mechanisms, and to the behavioral performances putatively linked to these substrates; Chapter 3 describes face processing both in adults and infants accordingly to an experience-dependent perspective.
Subsequently, in the second part of the dissertation I describe two studies aiming at investigating the role of face and non-face stimuli in biasing orienting of attention, by means of two attentive effects, already documented both in adults and infants. Importantly, adults and infants are administered the same experimental paradigms, and their eye movements are recorded by means of an eye-tracker system (ASL). In particular in Study 1 (Chapter 4) the modulation of the inhibition of return effect by social stimuli to the detriment of non-social stimuli is investigated in adults and 4- and 7-month-old infants. The inhibition of return refers to a bias against attending to visual stimuli at recently attended locations. I hypothesized that an upright face (social stimulus) that compared in the previously attended location, given its biological value, could escape this spatial tagging, when compared with inverted face and house (non-social stimuli). Results seems to confirm a overall modulation of the inhibition of return effect, that is different according to the different ages tested.
In Study 2 (Chapter 5) the gap effect is employed, with the aim to verify if the attention disengagement could be modulated by social stimuli to the detriment of non-social stimuli, in adults and 4- and 7-month-old infants. The gap effect consists in a reduction in the disengagement latency toward peripherally appearing targets when the fixation point disappears a short time before target (gap trials), compared to when both the fixation point and the peripheral target stay together on the screen (overlap trials). I hypothesized (Study 2a) that the disengagement latencies would be affected by the presence of an upright face (social stimulus) as fixation point or peripheral target more than an inverted or a noise face (non-social stimuli). Further I hypothesized (Study 2b) that the disengagement latencies would be affected by the presence of emotional expressions (social stimuli) as fixation point or peripheral target more than a noise face (non-social stimulus). Results seems to confirm a overall modulation of disengagement latencies only in the overlap trials by the social stimuli, but this modulation varies according to the different ages tested.
Overall the results confirm a modulation of orienting of attention by the nature of the stimuli employed, but, as hypothesized, given a different degree of experience with faces in infancy and adulthood, different is degree of influence of this stimuli on orientin
Number versus extent in newborns’ spontaneous preference for collections of dots
No full textThis study investigated processing of number and extent in newborns. Using visual preference, we showed that newborns discriminated between small sets of dot collections relying solely on implicit numerical information when non-numerical continuous variables were strictly controlled (Experiment 1), and solely on continuous information when numerical variables were controlled (Experiment 2). When number and extent were pitted against each other (Experiment 3), newborns showed no visual preference, suggesting that the two variables play comparable roles in attracting newborns’ visual attention. In contrast to reports of dominance of continuous variables, these findings suggest that multiple dimensions attract newborns’ attention and guide their visual exploratio
Detecting Fakers of the autobiographical IAT
No full textAutobiographical memories might be identified using a variant of the implicit association test (IAT), or the autobiographical IAT (aIAT). The IAT provides a measure of association between true sentences and sentences describing an autobiographical event. This tool might be used to evaluate whether specific autobiographical information is encoded within the respondent’s mind/brain. This paper examines possible problems arising when the aIAT is used as a lie-detector technique. The results indicate that, when given previous instruction or training with an aIAT, examinees can alter their results and beat the ‘memory-detector’. However, we have been able to detect successful fakers of aIATon the basis of their specific response patterns. Our algorithm has the ability to spot the faker in a satisfactory manner. If, as demonstrated here, faking can be detected, then the real autobiographical event might also be identified when the examinee attempts to alter their results
Facial expressions as a model to test the role of the sensorimotor system in the visual perception of the actions
No full textA long-term debate concerns whether the sensorimotor coding carried out during transitive actions observation reflects the low-level movement implementation details or the movement goals. On the contrary, phonemes and emotional facial expressions are intransitive actions that do not fall into this debate. The investigation of phonemes discrimination has proven to be a good model to demonstrate that the sensorimotor system plays a role in understanding actions acoustically presented. In the present study, we adapted the experimental paradigms already used in phonemes discrimination during face posture manipulation, to the discrimination of emotional facial expressions. We submitted participants to a lower or to an upper face posture manipulation during the execution of a four alternative labelling task of pictures randomly taken from four morphed continua between two emotional facial expressions. The results showed that the implementation of low-level movement details influence the discrimination of ambiguous facial expressions differing for a specific involvement of those movement details. These findings indicate that facial expressions discrimination is a good model to test the role of the sensorimotor system in the perception of actions visually presented
Newborns’ attention is driven by the translational movement
Full text linkThe present study investigated whether 2-day-old newborns are able to discriminate two
translating meaningless Point-Light Displays (PLD) videos, in which the shape of one of them
changes compared to that of the other along the trajectory, independently from movement
kinematics, and if this ability is present both when stimuli differed at the end or at the
beginning of the movement. To manipulate the instant in which along the movement the
difference between stimuli was evident, and to maintain every unspecific dissimilarity possibly
determining the preference, videos were played in a loop either forward or backwards. In
Experiment 1, PLD stimuli moved with natural accelerated-decelerated kinematics; in Experiment
2 they moved at constant velocity. Four groups of newborns were submitted to the preferential
looking technique experiments. Results showed that newborns looked longer at natural
kinematics and that, irrespective of the type of kinematics, they discriminated the two stimuli
only when videos were played forward, that is, only when stimuli differed at the end of the
movement. These data suggest that, independently from kinematics, movement translational
components induce newborns to allocate attention at the end of the observed movement.
Given the strict link between attention and eye movements, we suggest that this effect may
bootstrap the system and give rise to proactive gaze, the typical gaze behaviour present during
executed and observed goal-directed actions
Hyperthermic intraperitoneal chemotherapy (HIPEC) after primary debulking surgery in advanced epithelial ovarian cancer: is BRCA mutational status making the difference?
Full text linkThe role of a molecular pattern predictive of hyperthermic intraperitoneal chemotherapy (HIPEC) efficacy in advanced ovarian cancer (AOC) patients has been poorly investigated. We aimed to assess the effect of HIPEC after primary debulking surgery (PDS) in AOC according to patient's Breast Cancer Gene (BRCA) mutational status
Combining implicit and explicit techniques to reveal social desirability bias in electricity conservation self-reports
No full textWhile questionnaires are still the most common way to survey consumers’ behaviors, it is known that respondents’ answers can be affected by the social desirability attributed to the behavior under investigation. To check whether a social desirability bias also affects electricity consumption self-reports, a study was carried out adopting an explicit (questionnaire) and implicit measurement technique (the autobiographical Implicit Association Test). Three behaviors were probed in this way, with a sample of 180 participants (60 for each behavior). The analysis of the congruence between explicit and implicit answers confirms that desirability bias is at stake in self-reported measures of electricity conservation; it also shows that different behaviors—in this same domain—can be subject to this bias to a different extent and that a considerable amount of participants need to be considered as ambivalent. The methodological and conceptual implications of these findings and of the method are discussed with respect to pro-environmental studies and interventions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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