- Email: [email protected]
He has his mothers ears!
.That will
do nicely,
It seems intuitive that the inclusion of a recent photograph of the legal card holder on all credit cards would reduce fraudulent use and personation. After all, the literature suggests that recognition memory for faces is good. Indeed, there are moves towards the introduction of photo-credit and photo-identity cards in many countries around the world. But is there any empirical evidence to support this contention? A recent study reported by Kemp, Towell and Pike was explicitly designed to answer this question. They asked trained supermarket employees to judge whether the photographs on credit cards depicted the person tendering them. Each ‘customer’ was provided with a set of four credit cards in which the photograph on the card was either: (a) the cardholder; (b) the cardholder with a change in hairstyle or jewellery; (c) a person who looked similar to the cardholder; (d) a person who did not look like the cardholder. It is important note that the cardholder’s signature appeared on the reverse side of each card. Each cashier then processed 44 transactions in 90 minutes (a rate commensurate with the normal working speed of checkout cashiers). The cashiers were aware of the purpose of the study but did not know the precise design of the experiment. The results showed that although over half the transactions were fraudulent, the cashiers successfully accepted over 85% of the cards that contained an image
sir?
of the cardholder. However, the cashiers were surprisingly less accurate in rejecting bogus cards. Thus, they rejected only 66% of cards in which the photograph did not look like the cardholder and only 36% of those that were judged to bear a resemblance to the cardholder, but were not in fact the cardholder. The authors note that these results were obtained using high quality colour photographs that were prepared only six weeks prior to the test and that the bogus cardholders made no attempt to mimic the appearance of the real cardholder. It may be significant that the ‘customers’ presented the cards to the cashiers in a pseudorandom order and were therefore unaware of whether they were presenting a valid or invalid credit card. Notwithstanding the psychological issues raised by these results, they certainly appear to question the utility of the addition of photographs to credit cards as a means of combating fraudulent credit card use at the point of sale. Indeed, it is likely that the photograph on your credit card will be used for a lot longer than six weeks and any fraudulent user may be reasonably expected to make some attempt at mimicking your appearance. Reference Kemp,
R., Towell,
swng
should
credit
cards
N. and
not and
fraud
Appl.
Copyright
0 1997. Elsevier
Trends
in
Cognitive
Science
Ltd. All rights
Sciences
-
Vol.
Cogn.
When
photographs, Psycho/.
11.
211-222
He has his mothers We are all familiar with the subtle phonetic differences that provide some of the key features of human language. However, the acoustic characteristics of human speech are highly variable and may be modified by the gender or the identity of the speaker as well as the speed of speaking and other factors. This variability means that sorting a stream of speech into phonetic categories is a very complex and exacting business that forms a very important part of the process of human language acquisition. Moreover, phonetic units are often poorly specified in adult speech and may therefore provide a rather poor substrate for the acquisition of language skills by infants. While it has been suggested that the speech we direct at infants is syntactically, semantically and prosodically modified relative to the speech we direct towards adults, and that this may enhance language acquisition processes, until recently there was no direct evidence that the phonetic units are similarly modified in infant-directed speech. Kuhl et al. now report that the acoustic properties of the phonetic language units are altered in infant-directed speech
Pike, G. (1997)
be bellwing:
ears!
in three different languages: English, Russian and Swedish. Specifically, the parents were found to address their infants using acoustically stretched vowels that exaggerated the differences between contrasting phonetic categories and thereby highlighted the features that were used to distinguish between them. These results therefore suggest that the exaggerated ‘parentese’ that is frequently used by parents when addressing babies and young infants may provide more than just attentional and emotional support and encouragement. The authors propose that this may help to selectively tune babies into the specific sounds that distinguish between phonetic categories. Although, as the authors acknowledge, the question of whether the use of ‘parentese’ is essential for language acquisition remains to be answered, this study is certainly an important step in that direction.
Transitive inference and the hippocampus in rats Declarative memory, the ability to recollect specific events or facts, is thought to be dependent upon the hippocampal region in humans. A considerable research effort has been devoted to the question of whether a similar ability exists in other animal species and whether this ability is similarly dependent upon the hippocampus. There are however, obvious problems in the study of declarative memory in animals and these have restricted progress in this area. Two important properties of a declarative memory system, the ability to encode relationships between stimuli, and the ability to encode information in a flexible, inferential manner, have been more successfully studied. Indeed, there is considerable evidence that the hippocampus is involved in the relational and inferential abilities that are required for adequate navigation by rodents. However, it is possible that these abilities may be restricted to the spatial domain in lower species. Dusek and Eichenbaum have recently extended these studies into the area of nonspatial declarative memory using a test of transitive inference involving odour discriminations. Rats were trained on a set of four overlapping two-odour discriminations that could be learnt either individually (A > B, B > C, C > D, D > E) or as a single representation of the orderly relationships among the stimuli (A > B > C > D > E). Several probe tests were then used to identify which representational system was used to encode the information. One test was between two non-adjacent and non-end odours (B vs D). Although control rats were perfectly able to accurately select odour B in preference to odour D, thereby demonstrating robust transitive inference, rats that had previously had their hippocampus disconnected from either the cortical or subcortical pathways were not. In contrast, all control and lesioned animals correctly acquired the separate discrimination problems. These results therefore add weight to the view that the hippocampus mediates a more general declarative memory system in rodents as has been found to occur in humans. Reference
Reference
Dusek,
Kuhl, P.,K. eta/.
(1997)
phonetic
in language
Science
reserved. 1,
units
Cross-language addressed
277, 684-686
6.
September
of
to infants
1997
J.A.
and
hippocampus relations 7109-7114
1364.6613/97/417.00 No.
analysis
Eichenbaum,
and Proc.
memory
Nat!.
Acad.
H. (1997) for orderly
The
stimulus
Sci. U. 5. A.
94.
do nicely,
It seems intuitive that the inclusion of a recent photograph of the legal card holder on all credit cards would reduce fraudulent use and personation. After all, the literature suggests that recognition memory for faces is good. Indeed, there are moves towards the introduction of photo-credit and photo-identity cards in many countries around the world. But is there any empirical evidence to support this contention? A recent study reported by Kemp, Towell and Pike was explicitly designed to answer this question. They asked trained supermarket employees to judge whether the photographs on credit cards depicted the person tendering them. Each ‘customer’ was provided with a set of four credit cards in which the photograph on the card was either: (a) the cardholder; (b) the cardholder with a change in hairstyle or jewellery; (c) a person who looked similar to the cardholder; (d) a person who did not look like the cardholder. It is important note that the cardholder’s signature appeared on the reverse side of each card. Each cashier then processed 44 transactions in 90 minutes (a rate commensurate with the normal working speed of checkout cashiers). The cashiers were aware of the purpose of the study but did not know the precise design of the experiment. The results showed that although over half the transactions were fraudulent, the cashiers successfully accepted over 85% of the cards that contained an image
sir?
of the cardholder. However, the cashiers were surprisingly less accurate in rejecting bogus cards. Thus, they rejected only 66% of cards in which the photograph did not look like the cardholder and only 36% of those that were judged to bear a resemblance to the cardholder, but were not in fact the cardholder. The authors note that these results were obtained using high quality colour photographs that were prepared only six weeks prior to the test and that the bogus cardholders made no attempt to mimic the appearance of the real cardholder. It may be significant that the ‘customers’ presented the cards to the cashiers in a pseudorandom order and were therefore unaware of whether they were presenting a valid or invalid credit card. Notwithstanding the psychological issues raised by these results, they certainly appear to question the utility of the addition of photographs to credit cards as a means of combating fraudulent credit card use at the point of sale. Indeed, it is likely that the photograph on your credit card will be used for a lot longer than six weeks and any fraudulent user may be reasonably expected to make some attempt at mimicking your appearance. Reference Kemp,
R., Towell,
swng
should
credit
cards
N. and
not and
fraud
Appl.
Copyright
0 1997. Elsevier
Trends
in
Cognitive
Science
Ltd. All rights
Sciences
-
Vol.
Cogn.
When
photographs, Psycho/.
11.
211-222
He has his mothers We are all familiar with the subtle phonetic differences that provide some of the key features of human language. However, the acoustic characteristics of human speech are highly variable and may be modified by the gender or the identity of the speaker as well as the speed of speaking and other factors. This variability means that sorting a stream of speech into phonetic categories is a very complex and exacting business that forms a very important part of the process of human language acquisition. Moreover, phonetic units are often poorly specified in adult speech and may therefore provide a rather poor substrate for the acquisition of language skills by infants. While it has been suggested that the speech we direct at infants is syntactically, semantically and prosodically modified relative to the speech we direct towards adults, and that this may enhance language acquisition processes, until recently there was no direct evidence that the phonetic units are similarly modified in infant-directed speech. Kuhl et al. now report that the acoustic properties of the phonetic language units are altered in infant-directed speech
Pike, G. (1997)
be bellwing:
ears!
in three different languages: English, Russian and Swedish. Specifically, the parents were found to address their infants using acoustically stretched vowels that exaggerated the differences between contrasting phonetic categories and thereby highlighted the features that were used to distinguish between them. These results therefore suggest that the exaggerated ‘parentese’ that is frequently used by parents when addressing babies and young infants may provide more than just attentional and emotional support and encouragement. The authors propose that this may help to selectively tune babies into the specific sounds that distinguish between phonetic categories. Although, as the authors acknowledge, the question of whether the use of ‘parentese’ is essential for language acquisition remains to be answered, this study is certainly an important step in that direction.
Transitive inference and the hippocampus in rats Declarative memory, the ability to recollect specific events or facts, is thought to be dependent upon the hippocampal region in humans. A considerable research effort has been devoted to the question of whether a similar ability exists in other animal species and whether this ability is similarly dependent upon the hippocampus. There are however, obvious problems in the study of declarative memory in animals and these have restricted progress in this area. Two important properties of a declarative memory system, the ability to encode relationships between stimuli, and the ability to encode information in a flexible, inferential manner, have been more successfully studied. Indeed, there is considerable evidence that the hippocampus is involved in the relational and inferential abilities that are required for adequate navigation by rodents. However, it is possible that these abilities may be restricted to the spatial domain in lower species. Dusek and Eichenbaum have recently extended these studies into the area of nonspatial declarative memory using a test of transitive inference involving odour discriminations. Rats were trained on a set of four overlapping two-odour discriminations that could be learnt either individually (A > B, B > C, C > D, D > E) or as a single representation of the orderly relationships among the stimuli (A > B > C > D > E). Several probe tests were then used to identify which representational system was used to encode the information. One test was between two non-adjacent and non-end odours (B vs D). Although control rats were perfectly able to accurately select odour B in preference to odour D, thereby demonstrating robust transitive inference, rats that had previously had their hippocampus disconnected from either the cortical or subcortical pathways were not. In contrast, all control and lesioned animals correctly acquired the separate discrimination problems. These results therefore add weight to the view that the hippocampus mediates a more general declarative memory system in rodents as has been found to occur in humans. Reference
Reference
Dusek,
Kuhl, P.,K. eta/.
(1997)
phonetic
in language
Science
reserved. 1,
units
Cross-language addressed
277, 684-686
6.
September
of
to infants
1997
J.A.
and
hippocampus relations 7109-7114
1364.6613/97/417.00 No.
analysis
Eichenbaum,
and Proc.
memory
Nat!.
Acad.
H. (1997) for orderly
The
stimulus
Sci. U. 5. A.
94.