The Story of Luggage

It started as a trunk that serves as storage space for Christopher Columbus’ things, from navigation products down to his clothes. From then on, luggage has always been a part of a traveler’s life. Wherever he may go, luggage bags will always be that one thing that especially made to provide convenience and comfort for the traveler.

From the sturdy oak, cedar, and pine trees that were used before as materials in making trunks (the early type of luggage), and to the different types of modern luggage bags today that remarkable create fashion statements, luggage bags had continued to evolve in the industry with the function of giving mankind a storeroom for his belongings.

Today, luggage bags are being sold in the market with different sizes, types, color, and materials. Every luggage bags vary from one to another; hence, it is important to find the type of luggage bag that would best work for you.

Whether you are a frequent traveler or a sporadic vacationer, there will surely be one type of luggage bag that would give you the kind of service that you want.

To know more, here is a list of the types of luggage bags:

1. Carry-ons

2. Utility kits or toiletries

3. Casual or tote bags

4. Garment carriers and bags

5. Rolling Suitcases Continue ►

Conclusions

Deja vu is experienced by a majority of the population, and occurs about once a year in experients. The incidence decreases with age but increases with education and socioeconomic class.

Deja vu is more common under conditions of stress and fatigue, and it is experienced more frequently by persons who travel.

Societal acceptance of the phenomenon appears to have increased over recent decades. Though deja vu historically has been linked to temporal lobe epilepsy and schizophrenia, this association has not been convincingly demonstrated.

Explanations of the phenomenon have included (a) momentary alteration in the normal operation of two usually coordinated cognitive processes; (b) neurological dysfunction (seizure, slowed synaptic transmission); (c) implicit memory activation based on familiarity of processing, object, or gestalt configuration; and (d) unattended perception (under distraction) followed immediately by a fully aware perception.

Although the deja vu experience occupies a solid position in the popular culture, the community of research psychologists has been largely silent on the topic. It is hoped that the use of more sophisticated research techniques to help elucidate this illusion of recognition will change this situation and that the findings from such research efforts could expand the field’s understanding of routine memory functions. As Roediger and McDermott (2000) suggested, “distortions of memory provide a fertile ground for studying interesting and important psychological phenomena” (p. 123).

Attentional Explanations (Part 3)

Inattentional blindness

Related to this interpretation of the deja vu, recent research suggests that individuals often miss objects that are clearly visible if they are focused on some other object in the visual array. This inattentional blindness, extensively investigated by Mack and Rock (1998), could explain how an initial brief perception of objects in a scene can go undetected.

When an extraneous visual stimulus (e.g., shape, object, word) accompanies a target stimulus (e.g., cross) to which the participant is instructed to respond (e.g., Which line of the cross is longer?), the individual often misses seeing the extraneous stimulus. When the target stimulus is in the periphery and the extraneous (ignored) stimulus is in the center of the visual field (fovea), inattentional blindness is more likely than when the target stimulus is in the fovea and the extraneous stimulus is in the periphery. Individuals who fail to report the extraneous (e.g., word) stimulus still process it, as reflected in significant priming on a subsequent word stem completion task (Mack & Rock, 1998).

Such a paradigm, in which the stimulus is above threshold but unattended (rather than subthreshold), better models people’s natural perceptual experience (Merikle et al., 2001) and provides a more realistic framework for studying the deja vu experience. For example, one may enter a room talking on a cell phone or thinking about an upcoming meeting while looking directly at a particular stimulus, and moments later this same stimulus is consciously perceived and elicits a déjà vu. Perhaps one of the most blatant examples of inattention to suprathreshold stimuli is the “time gap” experience, in which one’s entire perceptual experience over several minutes (e.g., during highway driving) is unrecallable (Reed, 1979).

It is possible that an inhibitory mechanism underlies the inattentional blindness effect. In elaborating on Poetzl’s (1917/1960) earlier speculation, N. F. Dixon (1971) suggested that during an initial brief stimulus exposure there is “a rapid fragmentation of the sensory information, wherein ‘inhibition by interference’ causes parts of the stimulus field to interfere with the development of other parts” (p. 106). Thus, certain elements in the stimulus array may suppress or block the perception of other elements, similarly to lateral inhibition in the visual system (cf. Martindale, 1981). In a second glance at the scene immediately after the first, the initially inhibited portion of the visual scene is disinhibited and now matches the present perception. The possibility that inhibition–disinhibition underlies deja vu is supported by the fact that both inhibitory processes and deja vu frequency decrease with age.

The magnitude of negative priming interference, for which a response which is actively inhibited on one trial is more difficult to generate on the immediately succeeding trial, is much smaller with older than younger adults (Hasher, Stoltzfus, Zacks, & Rypma, 1991). If the visual inhibition of parafoveal elements similarly decreases with age, this would reduce the likelihood that inhibited features would later disinhibit and lead to a deja vu.

Attentional Explanations (Part 2)

Perceptual fluency

This model for the déjà vu experience was evaluated by Jacoby and Whitehouse (1989), who discovered that when a test word was briefly presented (and masked) at subthreshold levels immediately prior to presentation on a recognition test, individuals were more likely to call the word “old” compared with a word not briefly preceded by itself. They attributed this illusion that the word had occurred on a prior list to its facilitated processing (perceptual fluency) engendered by the immediately prior subliminal presentation. This fluency bias supposedly precipitates the common experience of having a word appear to “jump out from the page” when reading (Jacoby & Dallas, 1981, p. 333).

Similarly, when a primed perceptual element suddenly and forcefully stands out, and source identification is lacking, this may precipitate a déjà vu. Jacoby and Whitehouse related this finding directly to the deja vu phenomenon, but the paradigm is lacking the element of “this could not have happened here before.” In this type of experimental setting, participants logically can misattribute the word to having occurred in the prior experimental list rather than being convinced that they could not have experienced this word before.

There has been debate over whether participants in this particular paradigm are consciously aware of the masked prime word (Bernstein & Welch, 1991; Joordens & Merikle, 1992; Watkins & Gibson, 1988), but this issue does not undermine the potential relevance of this paradigm for modeling the deja vu phenomenon. In fact, a supraliminal perceptual experience corresponds to Titchener’s (1928) illustration above, and modifying the Jacoby-Whitehouse design to have a divided attention manipulation, rather than subliminal presentation, may better model the deja vu experience. Merikle, Smilek, and Eastwood (2001) summarized the literature on perception without awareness and indicated that there are numerous investigations that suggest that stimuli presented either subliminally or supraliminally (but unattended) consistently have a potential to influence subsequent behavior.

Attentional Explanations (Part 1)

The fourth framework for interpreting déjà vu is that an ongoing stream of perceptual experience is divided into two separate perceptions through distraction or inattention. A brief initial perception of a scene under diminished attention is followed immediately by a second perception under full attention. The second impression matches that experienced moments earlier under degraded attention, and the individual does not consciously identify the prior experience as moments old but rather attributes it to a more distant past. Many researchers have espoused different versions of this interpretation (Conklin, 1935; Heymans, 1904; Lalande, 1893; Osborn, 1884; Wigan, 1844), and Titchener (1928) provided the following, oft-cited illustration:

You are about to cross a crowded street, and you take a hasty glance in both directions to make sure of a safe passage. Now your eye is caught, for a moment, by the contents of a shop window; and you pause, though only for a moment, to survey the window before you actually cross the street. . . . The preliminary glance up and down, which ordinarily connects with the crossing in a single attentive experience, is disjointed from the crossing; the look at the window, casual as it was, has been able to disrupt the associative tendencies. As you cross, then, you think “Why, I crossed this street just now”; your nervous system has severed two phases of a single experience, both of which are familiar, and the latter of which appears accordingly as a repetition of the earlier. (pp. 187–188)

Leeds (1944) called this phenomenon split-perception and proposed that an eye blink could possibly divide these two successive perceptions. Mayer and Merckelbach (1999) even suggested that this type of double take may be part of routine perception. The first second of information processing may be a platform from which a “quick and dirty” unconscious processing can have important effects on subsequent reactions to the stimuli around us. Though Mayer and Merckelbach related their speculation to anxiety disorders, their ideas have clear relevance to the déjà vu phenomenon.

Finally, Krijgers Janzen (1958) speculated that an initial and unattended eidetic image matches a regular perception moments later. He argued that all people experience eidetic imagery occasionally and that regular eidetic imagers would experience déjà vu more frequently than individuals who have eidetic images infrequently.

Memory Explanations (Part 1)

An extensive literature documents that an individual’s response to a particular stimulus can be altered by a prior encounter in the absence of explicit (episodic) recollection of this previous experi-
ence (cf. Roediger & McDermott, 1993; Schacter, 1987). Speculation concerning implicit familiarity as a foundation for a deja vu was originally proposed more than a century ago by Osborn (1884), who suggested that individuals process a considerable amount of information without paying full conscious attention to it and that the subsequent reprocessing of this information may occasionally give rise to a sensation of subjective familiarity in the absence of recollection. What sets the deja vu experience apart from other implicit memory responses is an inordinately strong impression of familiarity in the absence of explicit recollection.

Not all models in this section provide a clear explanation of what causes this intense familiarity, but they do present reasonable frameworks within which the deja vu experience can be interpreted.

Conflict in source monitoring processes

According to the source monitoring framework (SMF; Johnson, Hashtroudi, & Lindsay, 1993; Mitchell & Johnson, 2000), as events are experienced, various features are encoded (perceptual, spatial, emotional, semantic details, temporal information, ongoing cognitive operations), depending on the processing that occurs. Remembering is a mental activity in which current mental experiences are attributed to past events on the basis of their qualitative characteristics and on the individual’s general knowledge and beliefs. Although deja vu has not been specifically interpreted within the SMF, it is relatively straightforward to do so. For example, suppose that you are excited about a first trip to Seattle, enter the airport terminal on your arrival, and have a strong deja vu experience. You know that you never have been in Seattle, but the terminal seems incredibly familiar.

According to the SMF, a deja vu experience could arise from the conflict in two types of source monitoring processes. That is, your attribution based on your general knowledge (of never having been in Seattle) is in conflict with the heuristic attribution that is most natural as based on qualities of the mental experience, which imply it is familiar from past perception. Such familiarity could arise from a number of different types of past events encoded in memory. Perhaps you have seen this airport setting in a movie, television documentary, or picture in a magazine, but your current mental experience does not include this additional information that would allow you to identify the source of the familiarity. If you had a sense of familiarity but could identify its source (e.g., a magazine article on the plane), you would not have a deja vu experience. If you could not identify the source of the familiarity but also thought it was likely that you might have been in Seattle before after all, you also might not have a deja vu experience.

Duplication of processing

Osborn (1884) suggested that it may not be the content of the memory that is duplicated in a deja vu but rather the particular cognitive processing that occurred on a prior occasion:

If at any time in our past lives we passed in actual experience or in imagination over a mental track, say a b c d e , and if to-day [sic] this track is again traversed, although the former experience itself may have been long forgotten, we have a sense that it has been through the mind before. . . . If the mind passes over only part of the former track, say b c d,we sometimes, in the dim recognition which arises, believe we have been over the whole before. (pp. 480–481)

This interpretation can account for why the strong familiarity essential to deja vu can occur in a completely novel setting.  Osborn’s position is similar to the theory of transfer appropriate processing (Kolers, 1973; Kolers & Roediger, 1984; Morris, Bransford, & Franks, 1977; Roediger, Weldon, & Challis, 1989), in which retrieval success depends on the correspondence between the way the information is processed during input and retrieval. If similar mental procedures occur on both occasions, then recollection probability is high. If the processes are dissimilar, the likelihood of remembering the information is low. Thus, if the processing of the new information duplicates the mental procedures that occurred with a prior but unrelated experience, an unexpected sense of familiarity and deja vu may result, even though the stimulus elements in both situations are different.

Neurological Explanations (Part 2)

Neural transmission delay

Another class of neurological interpretations assumes that the deja vu experience results from a momentary delay in neuronal transmission from the perceptual organ to the higher order processing centers of the brain. In one version, there is a slight increase in the normal time taken to transmit the message, due to a synaptic dysfunction, and this slight slowing in the routine processing time (several milliseconds) is misinterpreted as representing that the information is old (Grasset, 1904). Anjel (1896) noted that the fatigued state often accompanying deja vu may underlie this neural slowing, temporarily elongating the time between sensation and perception. The logic behind this position is vague and unspecified, and it seems at odds with research on perceptual fluency. More specifically, individuals interpret faster (easier) processing of information as indicating that the item has been experienced before (Jacoby, 1988; Jacoby et al., 1988). Thus, slower processing should imply that the information is new, not old.

Another version of this transmission delay interpretation involves two neuronal pathways rather than one and has more logical explanatory appeal than the single-pathway version. In the visual system, sensory information traverses multiple pathways between the sensory organ and the higher cortical centers (Goodale & Milner, 1992; Milner & Goodale, 1995; Schneider, 1969). In most instances, the information is first received cortically from the primary and then from the secondary pathway (Weizkrantz, 1986). When the normally brief difference in processing time between the two tracks becomes lengthened, the usually seamless integration of the two messages into a single perception becomes disrupted and is experienced as two separate messages (Comfort, 1977). The brain interprets the second version, through the slowed secondary track, as a separate perceptual experience, and thus the inappropriate feeling of oldness derives from the match with the first input processed moments earlier.

Another version of this dual-pathway speculation assumes that the primary perceptual pathway goes directly to the dominant hemisphere while the secondary pathway routes first through the nondominant and then to the dominant hemisphere (Ephron, 1963; Humphrey, 1923). When the delay of information from the nondominant to the dominant hemisphere is slightly extended, a deja vu results (Maudsley, 1889; Osborn, 1884; Weinand et al., 1994). A simpler version of this position is that the two hemispheres normally receive the same information simultaneously, but a slight delay of information to one hemisphere results in a déjà vu (Humphrey, 1923; Wigan, 1844). Weinand et al. (1994) and Ephron (1963) proposed that the preseizure electrical disturbance confined to one hemisphere may cause the slight temporal delay in the secondary pathway, resulting in deja vu. Ephron also speculated that a lesion in the nondominant hemisphere could occasionally slow information transmission from the nondominant to the dominant hemispheres, an interpretation he suggested could be tested during neurosurgical procedures through local anesthesia of the corpus callosum.

A final neurological interpretation of deja vu, also involving two perceptual pathways, assumes that the primary rather than the secondary pathway is delayed, causing the information from the secondary pathway to arrive slightly before that received from the primary pathway. Information from the primary pathway is routinely interpreted by the individual as the initial perception, so when this information arrives after the secondary pathway information it feels familiar because a “memory” match already exists, only milliseconds old (Comfort, 1977; Ephron, 1963).