Research Topics

Attention

In everyday life there are constantly competing demands on attention by the outside world as well as from internally generated goals. The need for mechanisms to arbitrate between these competing demands is straightforward so that they can be integrated, prioritized, or selected, to provide coherent and adaptive behavior. Research has suggested the existence of separate networks of attention: orienting—involved in moving attention in space; selection or executive control—responsible for processing relevant information and ignoring irrelevant information; and alerting—involved in changes in arousal. These networks involve different neural tissues.

Orienting of visual attention to a point of interest may originate at will, as when we decide to look at a particular location where something of interest is expected, or it may originate reflexively without intention when something captures our attention, as when we orient to a flash of light in the dark or to a movement in the periphery of our vision. We use cueing tasks to study both reflexive (exogenous) and controlled (endogenous) mechanisms of attention. We use this task with humans and also with fish (archer fish).

In order to study selective attention we create conflict situations in which the subject has to respond to one stimulus or to one aspect of the stimulus and ignore another stimulus or another aspect of the stimulus. In these situations the subject needs to focus on the target (a stimulus or an aspect of a stimulus) and ignore all the rest of the display. Examples for tasks used for studying this type of selection are the Stroop color naming and the flanker tasks. In the Stroop task color-words are presented in color and subjects are asked to name the color of the ink and ignore the meaning of the word. People are commonly slower in responding to incongruent (BLUE) than to neutral (XXXX) or to congruent (RED) conditions. This suggests that they cannot ignore the meaning of the word (i.e., a failure of selective attention). In the flanker task the relevant and irrelevant attributes are presented in separate locations, for example, when subjects must focus on a letter at the center of a screen and ignore the flanking letters. ]

Alertness is studied by using an infrequent cue (in most cases a tone) before the imperative stimulus. We study various aspects of alertness. For example, we examine whether effects of alertness can be dissociated from effects of temporal orienting of attention and the relationship between alertness and executive control.  

We have recently received a grant from the German-Israel Foundation (GIF) to study the role of the pulvinar in cognitive control. The grant title is: Cortical and subcortical contributions to cognitive control. Our German partners are:  Prof. Peter Weiss-Blankenhorn, Prof. Gereon Fink and Dr. Simone Vossel from the Institute of Medicine Forschungszentrum, Juelich.

Selected publications

Gabay, S., Henik, A., & Gradstein, L. (2010).Ocular motor ability and covert attention in patients with uane Retraction Syndrome.Neuropsychologia, 48, 3102-3109.

Goldfarb, L., Aisenberg, D., & Henik, A. (2011). Think the thought, walk the walk—social priming reduces the Stroop effect. Cognition, 118, 193-200.

Weinbach, N., & Henik, A. (2011). Phasic alertness can modulate executive control by enhancing global processing of visual stimuli. Cognition, 121, 454-458.

Aisenberg, D., & Henik, A. (2012). Stop being neutral – Simon takes control! The Quarterly Journal of Experimental Psychology, 65, 295-304.

Gabay, S., Avni, D., & Henik, A. (in press). Reflexive orienting by central arrows: Evidence from the inattentional blindness task. Psychonomic Bulletin & Review.

Klanthroff, E., Goldfarb, L., & Henik A. (in press).Evidence for interaction between the stop-signal and the Stroop task conflict.Journal of Experimental Psychology: Human Perception and Performance.

Weinbach, N., & Henik, A. (in press). The relationship between alertness and executive control.Journal of Experimental Psychology: Human Perception and Performance.

Numerical cognition

Numerical cognition is essential to many aspects of life and arithmetic abilities predict academic achievements better than reading. In recent years, researchers strive to understand the building blocks of numerical cognition, the neural tissue involved, and the developmental trajectories. An example for atypical development is developmental dyscalculia (DD) which is a congenital deficiency in the development of arithmetic abilities.

We are interested in basic mental operations involved in numerical cognition. For example, we study processes involved in the association of symbols (e.g., digits, words) with quantities, and brain structures that underlie these processes. The picture that appears here (a small 8 trying to climb the ladder to the top of a big 3) represents the fact that digit symbols have their own physical features (e.g., physical size) that may modulate their symbolic (i.e., numerical value) effect. These physical sizes could be employed to ask questions about digit representation and usage. For example, in our culture 8 represents a larger value or size than 3, hence, the appearance of 8 as (physically) smaller than 3 might produce a conflict. Namely, 8 has a larger numerical value than 3 but in this picture it is physically smaller than 3. Psychologists have been using similar conflict situations to study automaticity and selective attention.

We use the comparative judgment task in which a participant is presented with two numbers (e.g., 3 5) and asked to decide which one is numerically larger/smaller. This task gives rise to the distance effect-people respond faster when the two digits are further apart from one another (e.g., 3 8) than when they are close to one another (e.g., 6 8). It is possible to create a Stroop-like situation in which the digits differ not only in numerical value but also in physical size (e.g., 3 5). Commonly, people respond faster to congruent (e.g., digits that are both numerically and physically smaller/larger) than to incongruent pairs of digits-the size congruity effect. This suggests that people process the numerical values automatically (even when they are irrelevant to the task). In contrast, those with developmental dyscalculia show deficiencies in automatic processing of numerical values. Moreover, the size congruity effect involves the intraparietal sulcus (IPS) and deficiency presented by people with developmental dyscalculia might involve this area.
For more information: https://en.wikipedia.org/wiki/Numerical_Stroop_effect

In collaboration with the laboratory of Dr. Ronen Segev, from the department of life sciences, we started to study the Archer fish (see research in pictures and archer fish). Here we aim to study how animals without a developed cortex can execute various tasks such as comparative judgment or Stroop-like.

In collaboration with Professors Joseph Tzelgov and Andrea Berger from BGU and Dr. Orly Rubinsten from University of Haifa, we received from the Israel Science Foundation (ISF) support for a center of excellence to study the neurocognitive basis of numerical cognition. In addition, we recently received an ERC Advanced Researcher Grant to study effects of non-countable dimensions, i.e., the perception and evaluation of sizes and amounts, on numerical cognition. The grant title is: Size matters in numerical cognition.

Selected publications

Ashkenazi, S., Henik, A., Ifergane, G., & Shelef, I. (2008).Basic numerical processing in left intraparietal sulcus (IPS) acalculia.Cortex, 44, 439-448.

Rubinsten, O., & Henik, A. (2009). Developmental dyscalculia: Heterogeneity may not mean different mechanisms. Trends in Cognitive Sciences, 13, 92-99.

Ashkenazi, S., & Henik, A. (2010).A disassociation between physical and mental number bisection in developmental dyscalculia.Neuropsychologia, 48, 2861-2868.

Naparstek, S., & Henik, A. (2010). Count me in! On the automaticity of numerosity processing.Journal of Experimental Psychology: Learning, Memory, and Cognition, 36, 1053-1059.

Henik, A., Leibovich, T., Naparstek, S., Diesendruck, L., & Rubinsten, O. (2012).Quantities, amounts, and the numerical core system.Frontiers in Human Neuroscience,5:186. doi: 10.3389/fnhum.2011.00186

Naparstek, S., & Henik, A. (2012). Laterality briefed: Laterality modulates performance in a numerosity-congruity task. Consciousness and Cognition, 21, 444-450.

Synesthesia

Synesthesia means blending of senses. That is, sensory experiences (e.g., sound, taste) or concepts (e.g., words, numbers, time) automatically evoke additional precepts (e.g., color). The figure presents numbers in colors as seen by the first synesthete studied in our laboratory – MM. The majority of experimental work has focused on understanding the phenomenon in isolation. For example, research has attempted to reveal the mechanism(s) that underlies synesthesia or the stage(s) of processing on which the synesthetic experience depends. Independent of this line of research, however, the study of synesthesia may help to better understand the non-synesthetic mind. Understanding the phenomenon requires forays into fields such as perception, awareness, representation, development and neuroanatomy, and it therefore provides a good testing ground for many ideas and theories about different areas of cognitive science.Our research is aimed at unraveling the neurocognitive mechanisms of synesthesia and its implications for models of neurocognitive functioning.

We study both grapheme-color and number-form synesthesia. Number form synesthetes see numbers or months in space. An example for numbers in space is provided by synesthete SM (see research in pictures).

Selected publications

Cohen Kadosh, R., Cohen Kadosh, K., & Henik, A. (2007). The neuronal correlate of bi-directional synesthesia: A combined event-related potential and functional magnetic resonance imaging study. Journal of Cognitive Neuroscience, 19, 2050-2059.

Cohen-Kadosh, R., & Henik, A. (2007). Can synaesthesia research inform cognitive science? Trends in Cognitive Sciences, 11, 177-184.

Cohen Kadosh, R., Tzelgov, J., & Henik, A. (2008). A synesthetic walk on the mental number line: The size effect. Cognition, 106, 548–557.

Cohen Kadosh, R., Henik, A., Catena, A., Walsh, V., & Fuentes, L. J. (2009).Induced cross-modal synesthetic experience without abnormal neuronal connections.Psychological Science, 20, 258-265.

Gertner, L., Henik, A., & Cohen Kadosh, R. (2009). When 9 is not on the right: Implications from number-form synesthesia.Consciousness and Cognition, 18, 366-374.

Diesendruck, L., Gertner, L., Botzer, L., Goldfarb, L., Karniel, A., & Henik, A. (2011). Months in space: Synesthesia modulates attention and action. Cognitive Neuropsychology, 27, 665-679.

Arend, I., Gertner, L., & Henik, A. (in press). Perceiving numbers influences actions in number-space synesthesia. Cortex.

Emotion

Emotion is an essential aspect of our life.Many emotional stimuli are processed without being consciously perceived. Studies suggest that subcortical structures have a substantial role in thisprocessing. These structures are part of a phylogenetically ancient pathway that has specificfunctional properties and that interacts with cortical processes. In particular, it has been suggested that emotional stimuli have privileged access to higher cortical processing, which in turns explains the automaticity of such stimuli.

Our research focuses on the relationship between emotion and attention. In various studies we have suggested that emotional stimuli can be down regulated by higher cognitive processes and in particular by processes involved in cognitive control.

Selected publications

Okon-Singer, H., Tzelgov, J., & Henik, A. (2007). Distinguishing between automaticity and attention in the processing of emotionally-significant stimuli.Emotion, 7, 147-157.

Cohen, N., Henik, A., &Mor, N. (2011). Can emotion modulate attention? Evidence for reciprocal links in the attentional network test.Experimental Psychology, 58, 171-179.

Okon-Singer, H., Alyagon, U., Kofman, O., Tzelgov, J., & Henik, A. (2011). Fear-related pictures deteriorate performance of university students with high fear from snakes or spiders. Stress, 14, 185-193.

Lichtenstein-Vidne, L., Henik, A., & Safadi, Z. (2012). Task relevance modulates processing of distracting emotional stimuli. Cognition & Emotion, 26, 42-52.

Cohen, N., & Henik, A. (in press). Do irrelevant emotional stimuli impair or improve executive contro? Frontiers in Integrative Neuroscience.

Okon-Singer, H., Lichtenstein-Vidne, L., and Cohen, N. (2012).Dynamic modulation of emotional processing. Biological Psychologydoi:10.1016/j.biopsycho.2012.05.010

Word processing

Imagine that you are presented with a series of letters and asked to decide if this series is a word or a non-word. Various aspects of the presented stimulus and the experimental context affect performance. For example, concrete words (e.g., table) are processed faster than abstract (e.g., love) words, and responding to a word is facilitated if preceded by a semantically (or otherwise) related word (e.g., the word dog preceded by cat compared to dog preceded by chair)-the priming effect.

Psychologists have long suggested that our memory is organized as a network of concepts. In this network, associated or semantically related concepts are closer than non-associated or semantically unrelated concepts. This structure of the network gives rise to the priming effect. Within such a network one can examine various features of neighborhoods; how many neighbors a word has, how dense a given neighborhood is, etc. Aside from studying the automaticity of word processing, we have been investigating various features and effects of the semantic neighborhood and how individual differences in verbal abilities modulate these effects.

Selected publications

Henik, A., Dronkers, N., Knight, R., &Osimani, A. (1993). Differential effects of semantic and identity priming in patients with left and right hemisphere lesions. Journal of Cognitive Neuroscience, 5, 45-55.

Anaki, D., & Henik, A. (2003). Is there a "strength effect" in automatic semantic priming? Memory & Cognition, 31, 262-272.

Henik, A., Rubinsten, O., &Anaki, D. (Eds.).(2005). Word Norms in Hebrew.Ben-Gurion University of the Negev.

Ron-Kaplan, I., & Henik, A. (2007). Verbal ability modulates the associative neighbors effect. Psychonomic Bulletin & Review, 14, 81-87.