Taking the task seriously: reflections on measures of color acquisition

The experiments described in the lead articles by Kowalski and Zimiles and by O'Hanlon and Roberson examine factors that lead to color term acquisition. These experiments touch on the debate regarding the relative contributions of language and concepts in word learning. In this reflection, we examine how conclusions concerning the debate depend deeply on the particular task presented to children, and we propose an alternative approach to studying color term acquisition.     

The exponential learning equation as a function of successful trials results in sigmoid performance

While the exponential learning equation, indicating a gradually diminishing improvement, is one of the standard equations to describe learning, a sigmoid behavior with initially increasing then decreasing improvement has also been suggested. Here we show that the sigmoid behavior is mathematically derived from the standard exponential equation when the independent variable of the equation is restricted to the successful trials alone. It is suggested that for tasks promoting success-based learning, performance is better described by the derived sigmoid curve.     

Adolescents with learning disabilities: Psychic structures that are not conducive to learning

In this paper, I attempt to make links between theoretical concepts derived from the work of Bion (in particular, the 'ego-destructive super-ego', and the function he termed '-K' in thinking disorders) and the nature of the transference relationship that became evident in my clinical work with some adolescents with learning disabilities. I use three clinical examples to illustrate these ideas and suggest that learning can be facilitated for this patient group by addressing difficulties which arise in the therapist's countertransference related to the theoretical concepts cited above.     

Probabilities on Sentences in an Expressive Logic

Automated reasoning about uncertain knowledge has many applications. One difficulty when developing such systems is the lack of a completely satisfactory integration of logic and probability. We address this problem directly. Expressive languages like higher-order logic are ideally suited for representing and reasoning about structured knowledge. Uncertain knowledge can be modeled by using graded probabilities rather than binary truth values. The main technical problem studied in this paper is the following: Given a set of sentences, each having some probability of being true, what probability should be ascribed to other (query) sentences? A natural wish-list, among others, is that the probability distribution (i) is consistent with the knowledge base, (ii) allows for a consistent inference procedure and in particular (iii) reduces to deductive logic in the limit of probabilities being 0 and 1, (iv) allows (Bayesian) inductive reasoning and (v) learning in the limit and in particular (vi) allows confirmation of universally quantified hypotheses/sentences. We translate this wish-list into technical requirements for a prior probability and show that probabilities satisfying all our criteria exist. We also give explicit constructions and several general characterizations of probabilities that satisfy some or all of the criteria and various (counter)examples. We also derive necessary and sufficient conditions for extending beliefs about finitely many sentences to suitable probabilities over all sentences, and in particular least dogmatic or least biased ones. We conclude with a brief outlook on how the developed theory might be used and approximated in autonomous reasoning agents. Our theory is a step towards a globally consistent and empirically satisfactory unification of probability and logic.     

Synesthetic grapheme-color percepts exist for newly encountered Hebrew,Devanagari, Armenian and Cyrillic graphemes

Grapheme-color synesthetes experience color, not physically present, when viewing symbols. Synesthetes cannot remember learning these associations. Must synesthetic percepts be formed during a sensitive period? Can they form later and be consistent? What determines their nature? We tested grapheme-color synesthete, MC2, before, during and after she studied Hindi abroad. We investigated whether novel graphemes elicited synesthetic percepts, changed with familiarity, and/or benefited from phonemic information. MC2 reported color percepts to novel Devanagari and Hebrew graphemes. MC2 monitored these percepts over 6 months in a Hindi-speaking environment. MC2 and synesthete DN, reported synesthetic percepts for Armenian graphemes, or Cyrillic graphemes + phonemes over time. Synesthetes, not controls, reported color percepts for novel graphemes that gained consistency over time. Phonemic information did not enhance consistency. Thus, synesthetes can form and consolidate percepts to novel graphemes as adults. These percepts may depend on pre-existing grapheme-color relationships but they can flexibly shift with familiarity.     

School enrolment and executive functioning: A longitudinal perspective on developmental changes,the influence of learning context,and the prediction of pre-academic skills

The present two-year longitudinal study addressed developmental changes in different aspects of executive functioning (i.e., inhibition, updating, and cognitive flexibility) in a sample of 264 children aged between 5 and 7 years. Of special interest were issues of developmental progression over time, the influence of learning context and the predictive power of executive functions and school context for emerging academic skills. The results revealed pronounced improvements in all executive measures, both over time and as a function of age. For the learning context, small and age-dependent effects on executive skills were found. Inhibition uniquely contributed to the prediction of aspects of emerging academic skills, over and above chronological age and language skills.     

Effects of simple- and complex-place contexts in the multiple-context paradigm

In four experiments, a total of 384 undergraduates incidentally learned a list of 24 nouns twice in the same context (same-context repetition) or different contexts (different-context repetition). Free recall was measured in a neutral context. Experiments 1, 2, and 3 used a context repetition (same- or different-context repetition) × inter-study and retention intervals (10 min or 1 day) between-participants design. Context was manipulated by the combination of place, social environment, and encoding task (Experiment 1), place and social environment (Experiment 2), or place alone (Experiment 3). Experiment 4 used a context repetition × type of context (context manipulated by place or by place, social environment, and encoding task) between-participants design, with a 10-min inter-study interval and a one-day retention interval. The present results indicate that the determinant of the superiority of same- or different-context repetition in recall is the type of context. Implications of the results were discussed.     

Difference Scores in the Identification of Children with Learning Disabilities It's Time to Use a Different Method

In this article, we identify ten reasons why discrepancy scores (based on differences between IQ and reading achievement scores) provide an inadequate means for identifying children with reading disabilities. We recommend instead that children be identified simply on the basis of problems in reading skills, regardless of their IQs.     

No Time of Day Modulation or Time Stamp on Multiple Memory Tasks in Rats

Various demonstrations of “time stamp” effects in the animal learning literature have reinforced the idea that circadian information is encoded as part of a combined internal/external representation of context and that this contextual information is utilized for complex retrieval processes supporting memory. The goal of the present series of experiments is to assess this idea by manipulating training/testing circadian times on a battery of learning and memory tasks commonly used in the rodent. The data obtained from five experiments using four different learning and memory paradigms provide no evidence for “time stamp” effects on place memory, context memory (aversive or appetitive), or S-R habit learning.