Consciousness & Emotion - Volume 3, Issue 1, 2002

Aims. Currently, methylphenidate (MPH, trade name Ritalin) is the most widely prescribed medication for attention deficit/hyperactivity disorder (ADHD). We examined the ability of repeated MPH administration to produce a sensitized appetitive eagerness type response in laboratory rats, as indexed by 50-kHz ultrasonic vocalizations (50-kHz USVs). We also examined the ability of MPH to reduce play behavior in rats which may be partially implicated in the clinical efficacy of MPH in ADHD. Design. 56 adolescent rats received injections of either 5.0 mg/kg MPH, or vehicle each day for 8 consecutive days, and a week later received a challenge injection of either MPH or vehicle. Measurements. Both play behavior (pins) and 50-kHz USVs were recorded after each drug or vehicle administration. Results. MPH challenge produced a substantial 73% reduction in play behavior during the initial treatment phase, and during the last test (1 week post drug), 50-kHz USVs were elevated approximately threefold only in animals with previous MPH experience. Conclusions. These data suggest that MPH treatment may lead to psychostimulant sensitization in young animals, perhaps by increasing future drug-seeking tendencies due to an elevated eagerness for positive incentives. Further, we hypothesize that MPH may be reducing ADHD symptoms, in part, by blocking playful tendencies, whose neuro-maturational and psychological functions remain to be adequately characterized.

Many philosophers sharply distinguish emotions from feelings. Emotions are not feelings, and having an emotion does not necessitate having some feeling, they think. In this paper I reply to a set of arguments people use sharply to distinguish emotions from feelings. In response to some arguments these “anti-feeling theorists” use I examine and entertain a hedonic theory of emotion that avoids various anti-feeling objections. Proponents of this hedonic theory analyze an emotion by reference to forms of cognition (e.g., thought, belief, judgment) and a pleasant or an unpleasant feeling. Given this theory, emotions are feelings in some important sense of “feelings”, and these feelings are identified as particular emotions by reference to their hedonic character and the cognitive state that causes the hedonic feelings.

What are the states of consciousness in themselves, those pulses of mentality that follow one upon another in tight succession and constitute the stream of consciousness? William James conceives of each of them as being, typically, a complex unitary awareness that instantiates many features and takes a multiplicity of objects. In contrast, Brian O’Shaughnessy claims that the basic durational component of the stream of consciousness is the attention, which he understands to be something like a psychic space that is simultaneously occupied by several experiences. Whereas, according to the first conception, emotion is a feature of a temporal segment of the stream of consciousness and colors through and through each consciousness state that instantiates it, the second conception considers an emotion to be a distinct one of a system of simultaneous experiences that interact with each other, for example, limiting each other’s number and intensity. Among other matters discussed is the two theorists’ mutually contrasting conception of how the non-inferential awareness which we have of our states of consciousness is accomplished.

Working from both a phenomenological and a biological background, the conditions under which the emergence of intentionality occurs, are approached. This is done via two particularities of biological systems: the inside/outside distinction they exhibit and the fact that they are sensitive. The phenomenon of boundaries turns out to be a crucial issue in such an account. To start from a biological level is an indispensable preparation for a proper understanding of intentionality, phenomenologically conceived.