Can synaesthesia research inform cognitive science?

The renaissance of synaesthesia research has produced many insights regarding the aetiology and mechanisms that might underlie this intriguing phenomenon, which abnormally binds features between and within modalities. Synaesthesia is interesting in its own right, but whether it contributes to our knowledge of neurocognitive systems that underlie non-synaesthete experience is an open question. In this review, we show that results from the field of synaesthesia can constrain cognitive theories in numerical cognition, automaticity, crossmodal interaction and awareness. Therefore, research of synaesthesia provides a unique window into other domains of cognitive neuroscience. We conclude that the study of synaesthesia could advance our understanding of the normal and abnormal human brain and cognition.     

When 9 is not on the right: Implications from number-form synesthesia

Number-form synesthetes consciously experience numbers in spatially-defined locations. For non-synesthete individuals, a similar association of numbers and space appears in the form of an implicit mental number line as signified by the distance effect–reaction time decreases as the numerical distance between compared numbers increases. In the current experiment, three number-form synesthetes and two different non-synesthete control groups (Hebrew speaking and English speaking) performed a number comparison task. Synesthete participants exhibited a sizeable distance effect only when presented numbers were congruent with their number-form. In contrast, the controls exhibited a distance effect regardless of congruency or presentation type. The findings suggest that: (a) number-form synesthesia impairs the ability to represent numbers in a flexible manner according to task demands; (b) number-form synesthesia is a genuine tangible experience, triggered involuntarily; and (c) the classic mental number line can be more pliable than previously thought and appears to be independent of cultural-lingo direction.     

Synaesthesia: learned or lost?

The question why synaesthesia, an atypical binding within or between modalities, occurs is both enduring and important. Two explanations have been provided: (1) a congenital explanation: we are all born as synaesthetes but most of us subsequently lose the experience due to brain development; (2) a learning explanation: synaesthesia is related to some learning process during childhood. Three recent studies provide conflicting support for these explanations. Two studies supported the idea that synaesthesia is learned by showing that the frequency of everyday language implicitly modulates the synaesthetic experience. Another study argued that synaesthesia reflects basic, innate magnitude representations. In this paper we reassess these points of view, and show that it is possible for both to be valid. These findings are integrated into an interactive specialization account of development in order to explain the neuronal mechanism underlying synaesthesia.     

Automatic quantity processing in 5-year olds and adults

In this study adults performed numerical and physical size judgments on a symbolic (Arabic numerals) and non-symbolic (groups of dots) size congruity task. The outcomes would reveal whether a size congruity effect (SCE) can be obtained irrespective of notation. Subsequently, 5-year-old children performed a physical size judgment on both tasks. The outcomes will give a better insight in the ability of 5-year-olds to automatically process symbolic and non-symbolic numerosities. Adult performance on the symbolic and non-symbolic size congruity tasks revealed a SCE for numerical and physical size judgments, indicating that the non-symbolic size congruity task is a valid indicator for automatic processing of non-symbolic numerosities. Physical size judgments on both tasks by children revealed a SCE only for non-symbolic notation, indicating that the lack of a symbolic SCE is not related to the mathematical or cognitive abilities required for the task but instead to an immature association between the number symbol and its meaning.     

Task-relevance modulates the effects of peripheral distractors

The current study investigated whether task-relevant information affects performance differently from how information that is not relevant for the task does when presented peripherally and centrally. In three experiments a target appeared inside the focus of attention, whereas a to-be-ignored distractor appeared either in the periphery (Experiments 1 and 2) or at the centre (Experiment 3) of attention. In each trial the distractor carried both task-relevant and irrelevant information. The results confirmed the “task relevance” hypothesis: Task-irrelevant information affected performance only when it appeared at the centre of attention, whereas task-relevant information affected performance when it appeared inside as well as outside the main focus of attention. The current results do not support suggestions that spatial stimuli (e.g., arrows) draw attention automatically regardless of task relevance.     

Controlling Stroop effects by manipulating expectations for color words

An important characteristic of automatic processing is its uncontrollability. The Stroop phenomenon is regarded as a prototypical example of this characteristic of automatic processing, hence, the Stroop effect should not change when the percentages of color words versus neutral stimuli are manipulated to induce controlled processing. We found that Stroop interference decreased as the percentage of color words increased. Furthermore, the magnitude of the inhibitory component of the Stroop effect was negatively correlated with the percentage of color words; the facilitatory component was insensitive to the manipulation. These results suggest that the Stroop effect is controllable (see Logan, 1980) and that the locus of control is postlexical. The results also suggest that facilitation and inhibition are produced by different mechanisms and challenge those models of the Stroop phenomenon (e.g., Cohen, Dunbar, & McClelland, 1990; Phaf, Van der Heijden, & Hudson, 1990) that assume that a single processing mechanism causes facilitation and inhibition and that control affects facilitation and inhibition alike (Logan, 1980).     

Capacity demands of automatic processes in semantic priming

Ben-Gurion University of the Negev, Beer Sheva, Israel In three experiments, we examined the effects of prime-target stimulus onset asynchrony (SOA) and the proportion of related primes and targets (relatedness proportion, or RP) on semantic priming when the prime was either named or was searched for a specific letter. In Experiment 1, with an RP of. 50, priming occurred at SOAs of 240 and 840 msec when the prime was named, but no priming was found at either SOA when the prime was searched for a letter. In Experiment 2 the RP was either. 20 or. 80, and the SOA was set at 1, 700 msec; priming again was found in both conditions when the prime was named, but only in the RP.80 condition when a letter search task was performed on the prime. In Experiment 3, both the proportion of related trials and SOA were varied; as in the previous experiments, no priming effects were found with the letter search task for either SOA in the RP.20 condition, but the priming effect was reinstated in the RP.80 condition. These results are discussed with respect to how limited capacity resources are allocated and how they influence semantic priming effects.     

Working mother-infant interactions across the second year of life

Play interactions between 36 college-educated, middle-income, working mothers and their infants, who had attended nursery school since 1 month of age, were videotaped when the infants were 12, 18, and 24 months of age. The videotapes were coded for mother and infant looking at each other, vocalizing, affectionate play, and constructive play. Changes noted in the infants' play behaviors across this period included an increase in infant vocalizations and constructive play and a decrease in affectionate play. These results, together with corresponding decreases in the mothers' constructive and affectionate play behavior, suggest growing autonomy of the infants' play and encouragement of autonomy by the mothers. Stability of behaviors across this period and stability of relations between infant and mother behaviors were only moderate. Comparison of these data with data from a study by Clarke-Stewart and Hevey (1981) suggested greater frequency of interactive behavior among working mothers and their infants than among nonworking mothers and their infants.     

The Development of Professional Counseling in Botswana

Among African countries, Botswana stands out for achieving lasting political and economic stability, which has enabled the government to develop a strong system of educational and social services for its people. Development of professional counseling in the country has occurred both through targeted efforts to provide a strong system of guidance services in schools and in response to the impact of the HIV/AIDS epidemic. This article reviews the development of professional counseling in Botswana and highlights trends likely to shape its future.