Examining Pinterest as a Curriculum Resource for Negative Integers: An Initial Investigation

This paper reports an investigation of mathematical resources available on the social media site Pinterest. Pinterest is an online bulletin board where users create visual bookmarks called pins in order to share digital content (e.g., webpages, images, videos). Although recent surveys have shown that Pinterest is a popular reference for teachers, understanding of the mathematical resources available on the site is lacking. To take initial steps in investigating the curriculum resources provided by Pinterest, we used keyword searches to gather a database of pins related to the topic of negative integers. A content analysis was conducted on the pins with a focus on several characteristics including mathematical operations, mathematical models, use of real-world context, and whether mathematical errors were present in source material. Results show a dominance of addition and subtraction over other operations, use of mathematical models in half of pins, infrequent use of real-world context, and mathematical errors in roughly one-third of pins. We provide a breakdown of these results and discuss implications of the findings for mathematics teacher education and professional development

Electronic structure and dynamics of optically excited single-wall carbon nanotubes

We have studied the electronic structure and charge-carrier dynamics of individual single-wall carbon nanotubes (SWNTs) and nanotube ropes using optical and electron-spectroscopic techniques. The electronic structure of semiconducting SWNTs in the band-gap region is analyzed using near-infrared absorption spectroscopy. A semi-empirical expression for $E_{11}^{\rm S}$ transition energies, based on tight-binding calculations is found to give striking agreement with experimental data. Time-resolved PL from dispersed SWNT-micelles shows a decay with a time constant of about 15 ps. Using time-resolved photoemission we also find that the electron-phonon ({\it e-ph}) coupling in metallic tubes is characterized by a very small {\it e-ph} mass-enhancement of 0.0004. Ultrafast electron-electron scattering of photo-excited carriers in nanotube ropes is finally found to lead to internal thermalization of the electronic system within about 200 fs.Comment: 10 pages, 10 figures, submitted to Applied Physics

Depression and Memory: Are Impairments Remediable Through Attentional Control?

People who are in depressed mood states or who are formally diagnosed as clinically depressed frequently complain of impaired memory. Such complaints have been substantiated by laboratory research, most of which supports the theoretical assumption that attentional resources play a causal role in producing the impairments. Specific theoretical frameworks do differ, however, in the proposed nature of this role and in their corresponding implications for remediation. The most prevalent positions are versions of a capacity framework (e.g., cognitive effort or resource allocation). 1 If you are depressed, according to the capacity framework, your attentional resources are either reduced neurochemically or allocated pervasively to matters of personal concern. Either way, if the task at hand requires hard thinking, your performance is impaired by the insufficiency of attentional resources. Presumably, the lifting of the impairment awaits successful psychopharmacological treatment or resolution of your personal concerns

Improving Memory and Mood Through Automatic and Controlled Procedures of Mind

Memory procedures and emotional states function together. Affective tone permeates episodes of memory functioning. Memory functions centrally in episodes of emotional disturbance, serving to feed the episode with fuel from past events or to repress those events when one hopes to escape or avoid the episode. When cognitive procedures are impaired by emotional states such as depression and anxiety, people do not perform the tasks and achieve the goals that could help to repair their moods. In the context of these considerations, then, we must view the improvement of memory as not merely a possible outcome of change in emotional states, but as a factor in effecting such change. Memory improvement and mood improvement function together

Cognition in Emotional Disorders: An Abundance of Habit and a Dearth of Control

Emotional and other psychological disorders are categories of experience identified at least in part by the goal of having treatment plans for people in distress. Because the categories exist for such purposes, research efforts are organized to discover distinctions among the categories and between disordered and nondisordered individuals. Many of these distinctions are cognitive. When clinical scientists began experimental studies, the term “cognitive” had been used to refer primarily to conscious thoughts that characterize disorders (see Beck, 1976), but in more recent decades the term signifies an experimental approach framed according to the theories and paradigms of cognitive psychology. In honor of Larry Jacoby’s contributions to cognitive psychology, this essay first describes experimental evidence regarding the cognitive habits of anxious and depressed individuals—habits that are quite similar across the disorders. Attention, interpretation, and memory tasks reveal negative biases that reflect well practiced tendencies. Next, the essay briefly reviews the results of recent efforts to modify negative biases. I argue that attempts to overcome habits via controlled procedures or by external constraints seem to be less successful than attempts to develop new habits. In depression, at least, habits are accompanied by difficulties in mustering opposition to them. Ultimately, the next important step in understanding cognitive contributions to emotional disorders is to take a more process-analytic approach. Toward the end of the essay I show how process-dissociation procedures (Jacoby, 1991) can be used to investigate the basis for clinically relevant change

Emotion, Mood, and Memory

The ways in which we attend, learn, and remember are related to our transitory moods and to our enduring emotional states. This assertion is based on research performed by experimental and clinical psychologists who use a variety of methods. In some studies, psychologists measure differences in emotional states and determine whether those differences are associated with differences in the ways that the participants perform cognitive tasks. These studies usually focus on unpleasant emotions and moods, such as depression and anxiety. In other studies, psychologists attempt to induce either unpleasant or pleasant moods in the participants (perhaps by having them listen to different types of music) and then examine how performance is affected by these manipulations. Both types of research have tried to answer three major questions about the interaction of mood and memory: (a) Do depressed and anxious moods hinder performance on cognitive tasks? (b) Do people remember events that are emotionally consistent with their moods better than other events? (c) Is performance improved if the same mood exists on the occasions of the original experience and the attempt to remember it? The ensuing summary suggests answers to the questions in the context of theoretical frameworks for understanding the relationships between mood and memory

Memory for Emotional and Nonemotional Events in Depression: A Question of Habit?

The truest claim that cognitive science can make might also be the least sophisticated: the mind tends to do what it has done before. In previous centuries philosophers and psychologists invented constructs such as associations, habit strength, and connectivity to formalize the truism, but others have known about it, too. In small towns in the Ozarks, for example, grandmothers have been overheard doling out warnings such as, Don\u27t think those ugly thoughts; your mind will freeze that way. Depressed persons, like most of us, usually don\u27t heed this advice. The thoughts frozen in their minds might not be ugly, but they often reflect disappointments, losses, failures, other unhappy events, and a generally negative interpretive stance toward ongoing experience. By considering these habits of thinking, we should better understand the nature of memory in depressed states. Deliberate attempts to remember are either impaired or facilitated in ways that appear related to habits of thinking. Even more commonly, memory is expressed indirectly through the content of current thoughts and interpretations

The Cognitive-Initiative Account of Depression-Related Impairments in Memory

The many and diverse interpretations of the word control make it clear that control constitutes a fundamental concern in most areas of psychology. In an illustration of this diversity, I described my interest in controlled uses of memory at a social gathering; my new acquaintances, without realizing the non sequitur, subsequently raised issues about self control and loss of control-issues much more relevant to their own interests in psychological phenomena than are my narrow musings. Yet a second thought devoted to the semantics of control reveals underlying commonalities. For example, when older people begin to have problems with controlled uses of memory, they sometimes feel like they are losing control in a more general sense

The Generation Effect: A Reflection of Cognitive Effort?

In incidental learning tasks, subjects generated words from anagrams or incomplete sentences, verified that the words solved the anagrams or fit in the sentences, or evaluated which rule had been used to construct the word from the anagram or sentence. Latencies in responding to a tone during these trials were used as a measure of cognitive effort. The results indicated that, in comparison to verification, the relatively effortless generation of words benefited memory, but the effortful decisions about the rules did not. Clearly, cognitive effort does not always announce better memory